Apparatus and methods for fiber integration and registration

ABSTRACT

Systems and methods for integrating and/or registering a shape sensing fiber in or to various instruments are described herein. Registration fixtures and registration techniques for matching the coordinate system of a fiber to the coordinate system of an elongate instrument or other device are provided. Various systems and methods for integrating a shape sensing fiber into an elongate instrument or other device are also described herein.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/258,470 filed Sep. 7, 2016, issued as U.S. Pat. No. 10,667,720 onJun. 2, 2020, entitled “Apparatus and Methods for Fiber Integration andRegistration,” which is a continuation of U.S. patent application Ser.No. 14/860,291 filed Sep. 21, 2015, now abandoned, entitled “Apparatusand Methods for Fiber Integration and Registration,” which is acontinuation of U.S. Non-Provisional patent application Ser. No.13/314,057, now U.S. Pat. No. 9,138,166, filed Dec. 7, 2011, entitled“Apparatus and Methods for Fiber Integration and Registration,” whichclaims the benefit of U.S. Provisional Patent Application No.61/513,488, filed Jul. 29, 2011. The above-referenced patentapplications are all incorporated herein by reference in theirentireties for all purposes.

This application is also related to and incorporates herein by referencein its entirety for all purposes U.S. patent application Ser. No.12/837,440, now U.S. Pat. No. 8,780,339, filed Jul. 15, 2010, entitled“Fiber Shape Sensing Systems and Methods.”

FIELD OF THE INVENTION

The present apparatus, systems and methods relate generally to apparatusand methods for integrating and/or registering a shape sensing fiber inor to an instrument or device.

BACKGROUND

Currently known minimally invasive procedures for diagnosis andtreatment of medical conditions use elongate instruments, such ascatheters or more rigid arms or shafts, to approach and address varioustissue structures within the body. For various reasons, it is valuableto be able to determine the 3-dimensional spatial position of portionsof such elongate instruments relative to other structures, such as theoperating table, other instruments, or pertinent tissue structures.Conventional technologies such as electromagnetic position sensors maybe utilized to measure 3-dimensional spatial position but may be limitedin utility for elongate medical instrument applications due to hardwaregeometric constraints, electromagnetivity issues, etc. An alternativesolution is the use of optical fibers containing optic shape sensors,available from suppliers such as Luna Innovations, Inc., of Blacksburg,Va., Micron Optics, Inc., of Atlanta, Ga., LxSix Photonics, Inc., ofQuebec, Canada, and Ibsen Photonics A/S, of Denmark. By integrating anoptical fiber into an elongate instrument such as a catheter, the realtime 3-dimensional spatial shape of any or all of the length of thecatheter may be determined.

Catheter structures may be designed to include an optical fiber.However, large strain changes induced by mechanical structures (such aspinching, twisting, etc.) may disrupt the accuracy of shape algorithms.The addition of components to a catheter may negatively affect theperformance of a catheter (such as stiffness, inner and outer diameters,etc.).

There remains a need for apparatus and methods to improve integrationand registration of a shape sensing fiber in or to an elongateinstrument or other device and/or to a mechanical structure that ismeaningful to the instrument or device/system.

BRIEF SUMMARY

In certain variations, various apparatus, systems and methods forintegrating and/or registering a shape sensing fiber in variousinstruments, for example, an elongate instrument are described herein.Such systems and methods may allow for the shape detection of anelongate instrument or other structure.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. The system may also include a shape sensing fiber, where atleast a first portion of the fiber is positioned in the lumen of theelongate instrument. A second portion of the fiber may be fixed orotherwise attached in a known location or position relative to theelongate instrument or to another structure such that the coordinatesystem of the fiber can be matched to the coordinate system of theelongate instrument to register the fiber to the elongate instrument. Asa result of this registration, the shape of an elongate instrument maybe detected or determined.

In certain variations, a method for registering a fiber to an elongateinstrument and/or detecting the shape of an elongate instrument mayinclude one or more of the following steps. An assembly having anelongate instrument and a shape sensing fiber may be operated. Theelongate instrument may have a proximal end, a distal end and at leastone lumen defined therein, where least a first portion of the fiber maybe positioned in the lumen of the elongate instrument. At least a secondportion of the fiber may be fixed in a known location or positionrelative to the elongate instrument or to another structure. A positionof the fixed portion of the fiber may be measured or ascertainedrelative to the elongate instrument to match the coordinate system ofthe fiber with the coordinate system of the elongate instrument toregister the fiber to the elongate instrument.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. The system may also include a shape sensing fiber, wherein atleast a first portion of the fiber is positioned in the lumen of theelongate instrument. A second portion of the fiber may be configured ina known shape, plane or other orientation relative to the elongateinstrument or to another structure such that the coordinate system ofthe fiber may be matched to the coordinate system of the elongateinstrument to register the fiber to the elongate instrument.

In certain variations, a method of detecting the shape of an elongateinstrument may include one or more of the following steps. Operating anassembly having an elongate instrument and a shape sensing fiber, wherethe elongate instrument may have a proximal end, a distal end and atleast one lumen defined therein may be performed. At least a firstportion of the fiber may be positioned in the lumen of the elongateinstrument and at least a second portion of the fiber may be configuredin a known shape, plane or other orientation. A position of the secondportion of the fiber may be measured or ascertained relative to theelongate instrument to match the coordinate system of the fiber with thecoordinate system of the elongate instrument to register the fiber tothe elongate instrument.

In certain variations, a method for detecting the shape of an elongateinstrument may include one or more of the following steps. Operating anassembly having an elongate instrument and a shape sensing fiber may beperformed. The elongate instrument may have a proximal end, a distal endand at least one lumen defined therein. At least a first portion of thefiber may be positioned in the lumen of the elongate instrument and atleast a second portion of the fiber may be fixed in a known locationrelative to the elongate instrument or to another structure. Savedregistration data may be accessed regarding registration between thecoordinate system of the fiber and the coordinate system of the elongateinstrument from a memory component to determine the shape of theelongate instrument. Optionally, the structure may be a registrationfixture which may be positioned in a known location relative to theelongate instrument.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and one or more lumens definedtherein. The system may include a shape sensing fiber, where at least aportion of the fiber may be positioned within the lumen of the elongateinstrument. The shape sensing fiber may have a service loop which allowsfor sliding or displacing of the fiber within the lumen of the elongateinstrument when a distal portion of the elongate instrument isarticulated, bent, navigated or manipulated. The system may also includea coil positioned within the lumen, and surrounding the fiber. The coilmay be slideable within the lumen and the coil may maintain the lumen inan open state during articulation of the elongate instrument.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. The system may include a housing coupled to a proximal portionof the elongate instrument, where the housing includes an interface forreceiving an actuating force and transferring the actuating force to theelongate instrument to articulate a distal portion of the elongatedinstrument. The system may also include a shape sensing fiber. At leasta first portion of the fiber may be positioned within the lumen of theelongate instrument, and a second portion of the fiber may be positionedwithin the housing. The second portion of the fiber may include aservice loop which allows for sliding or displacing of the fiber withinthe lumen of the elongate instrument when the distal portion of theelongate instrument is articulated.

In certain variations, a method of actuating an elongate instrument mayinclude one or more of the following steps. A system may be operativelycoupled to a controller. The system may include an elongate instrument;a housing coupled to a proximal portion of the elongate instrument,where the housing comprises an interface for receiving an actuatingforce and transferring the actuating force to the elongate instrument toarticulate a distal portion of the elongate instrument; and a shapesensing fiber. The elongate instrument may have a proximal end, a distalend and at least one lumen defined therein. At least a first portion ofthe fiber may be positioned within the lumen of the elongate instrument,and a second portion of the fiber may be positioned within the housing.The second portion of the fiber may include a service loop. Actuatingmotion may be transferred from the controller to the system toarticulate the distal portion of the elongate instrument in at least onedegree of freedom, where the service loop allows the fiber to slide orbe displaced within the lumen of the elongate instrument when the distalportion of the elongate instrument is articulated, thereby controllingthe amount of strain the fiber is subjected to and maintaining shapesensing properties of the fiber.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. A housing may be coupled to a proximal portion of the elongateinstrument, wherein the housing includes an interface for receiving anactuating force and transferring the actuating force to the elongateinstrument to articulate a distal portion of the elongate instrument.The system also includes a shape sensing fiber. At least a first portionof the fiber may be positioned in the lumen of the elongate instrument.At least a second portion of the fiber may be positioned in the housingsuch that the coordinate system of the fiber can be matched to thecoordinate system of the elongate instrument to register the fiber tothe elongate instrument. The second portion of the fiber may include aservice loop which allows for sliding or displacing of the fiber withinthe lumen of the elongate instrument when the distal portion of theelongate instrument is articulated.

In certain variations, a method of actuating an elongate instrument mayinclude one or more of the following steps. An assembly may beoperatively coupled to a controller. The assembly may include anelongate instrument; a housing coupled to a proximal portion of theelongate instrument, wherein the housing comprises an interface forreceiving an actuating force and transferring the actuating force to theelongate instrument to articulate a distal portion of the elongateinstrument; and a shape sensing fiber. At least a first portion of thefiber may be positioned in the lumen of the elongate instrument. Atleast a second portion of the fiber may be positioned in the housingsuch that the coordinate system of the fiber can be matched to thecoordinate system of the elongate instrument to register the fiber tothe elongate instrument. The second portion of the fiber may include aservice loop. Actuation motion may be transferred from the controller tothe assembly to articulate the distal end of the elongate instrument inat least one degree of freedom. The service loop may allow the fiber toslide or displace within the lumen of the elongate instrument when thedistal portion of the elongate instrument is articulated, therebycontrolling the amount of strain the fiber is subjected to. Savedregistration data regarding registration between the coordinate systemof the fiber and the coordinate system of the elongate instrument may beaccessed from a memory component to determine the shape of the elongateinstrument.

In one variation a method for integrating a shape sensing fiber in anelongate instrument may include inserting a fiber into a first lumen ofthe elongate instrument. The elongate instrument may include a supportcomponent positioned therein for maintaining patency of or otherwisesupporting the first lumen during articulation of the elongateinstrument. A distal end of the fiber may be fixed at a distal end ofthe elongate instrument and the fiber may remain free to slide or floatwithin the first lumen of the elongate instrument.

In certain variations, an elongate instrument is provided. The elongateinstrument may be configured to support the integration of a shapesensing fiber. The elongate instrument may include one or more lumensdefined through the elongate instrument and one or more fibers. A distalend of a fiber may be fixed to a distal end of the elongate instrument.A support component may be positioned within the elongate instrument tomaintain patency of or otherwise support one or more lumens duringarticulation of the elongate instrument. This may allow the fiber toslide or float within a lumen of the elongate instrument. Optionally,the fiber may include a service loop. Optionally, a registration fixturemay be coupled to the elongate instrument. The registration fixture mayhave grooves for holding a fiber and/or an elongate instrument incertain shapes or orientations.

In certain variations, a method for registering a shape sensing fiber toan elongate instrument is provided. The method may include fixing atleast a portion of the fiber to the elongate instrument or to astructure associated with the elongate instrument or providing anelongate instrument having a fiber fixed thereto or to an associatedstructure. Zero to six degrees of freedom may be ascertained from thefixed portion of the fiber. The location and/or orientation of the fixedportion of the fiber relative to the elongate instrument or to astructure associated with the elongate instrument may be determined tomatch the coordinate system of the fiber to the coordinate system of theelongate instrument, thereby registering the fiber to the elongateinstrument.

In certain variations, a system is provided. The system may allow forthe registering of a shape sensing fiber to an elongate instrument. Thesystem may include a registration fixture configured to hold theelongate instrument and/or the complete length or a partial length of afiber integrated in the elongate instrument in known positions ororientations such that data regarding the position or orientation of thepartial or complete length of the fiber may be collected to calculate atransform between the coordinate system of the fiber and the coordinatesystem of the elongate instrument.

In certain variations, another method of registering a shape sensingfiber to an elongate instrument is provided. A known shape may beinserted or imposed in a fiber. The location of the known shape relativeto a point on the elongate instrument or on a structure associated withthe elongate instrument may be determined. The known shape in the fibermay be measured to create a transform between a fiber coordinate systemand an elongate instrument coordinate system.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A illustrates a conventional manually-steerable catheter.

FIG. 1B illustrates a robotically-driven steerable catheter.

FIG. 2A illustrates a cross sectional view of a variation of an elongateinstrument having lumens for incorporating a fiber.

FIG. 2B illustrates a cross sectional view of a variation of an elongateinstrument having a symmetrical or uniform structure.

FIGS. 3A-3C illustrate cross sectional views of variations of anelongate instruments having fibers placed at various positions inrelation to several control wires.

FIGS. 4A-4C illustrate cross sectional views of variations of elongateinstruments having fibers placed at various positions in relation toseveral control wires.

FIG. 5 illustrates a cross sectional view of a variation of an elongateinstrument having fiber lumens positioned therein.

FIGS. 5A-5B illustrate cross sectional views of a variation of anelongate instrument having a coil pipe positioned inside a lumen of theelongate instrument. A fiber is positioned inside the coil pipe.

FIGS. 5C-5D illustrate cross sectional views of variations of anelongate instrument having a lumen for a fiber incorporated into thebraid of the elongate instrument.

FIGS. 6A-6B illustrate a variation of a fiber termination integrated inthe tip of an elongate instrument.

FIG. 7, illustrates a variation of a fiber having various accessoriesfor fulfilling shape sensing requirements when integrated into anelongate instrument.

FIGS. 8A-8D show a variation of a process for integrating a fiber into acatheter assembly

FIG. 9A shows a variation of a registration fixture positioned on acatheter assembly having a groove for positioning a fiber in a bird'seye shape.

FIG. 9B shows a top view of the registration fixture of FIG. 9A.

10A-10C show top views of variations of registration fixtures forpositioning a fiber in various shapes or configurations.

FIGS. 11-12 show a variation of a registration fixture for registering ashape sensing fiber to an elongate instrument

FIG. 13 shows a variation of a registration fixture for registering ashape sensing fiber to an elongate instrument.

FIG. 14A-14B show variations of registration fixtures for performingregistration.

FIG. 15 shows another variation of a registration fixture for receivingfiber slack.

FIG. 16 shows a flow chart for a variation of a method of integrating afiber into an elongate instrument.

FIGS. 17A-17B show a variation of an elongate instrument having a fiberwrapped around at least a portion of the elongate instrument.

FIG. 18 shows a variation of a manually steerable elongate instrumenthaving an integrated fiber.

FIG. 19 shows a flow chart showing one variation of a method forregistering a fiber to an elongate instrument or other structure.

FIG. 20 shows a perspective view of a surgical system with a shapesensing system mounted therein.

DETAILED DESCRIPTION

Variations of the devices, systems and methods described herein are bestunderstood from the detailed description when read in conjunction withthe accompanying drawings. It is emphasized that, according to commonpractice, the various features of the drawings may not be to-scale. Onthe contrary, the dimensions of the various features may be arbitrarilyexpanded or reduced for clarity. The drawings are taken for illustrativepurposes only and are not intended to define or limit the scope of theclaims to that which is shown.

Steerable Catheters (and Other Elongate Instruments)

Referring to FIG. 1A, a conventional manually-steerable catheter (1) isdepicted. Pullwires (2) may be selectively tensioned throughmanipulation of a handle (3) on the proximal portion of the catheterstructure to make a more flexible distal portion (5) of the catheterbend or steer controllably. The pull wires can run from the proximal todistal end of the catheter terminating at a control ring positioned nearthe distal tip of the catheter. The handle (3) may be coupled, rotatablyor slidably, for example, to a proximal catheter structure (14) whichmay be configured to be held in the hand, and may be coupled to theelongate portion (15) of the catheter (1). A more proximal, andconventionally less steerable, portion (4) of the catheter may beconfigured to be compliant to loads from surrounding tissues (forexample, to facilitate passing the catheter, including portions of theproximal portion, through tortuous pathways such as those formed by theblood vessels), yet less steerable as compared with the distal portion(5).

Referring to FIG. 1B, a robotically-driven steerable catheter (6),similar to those described in detail in U.S. patent application Ser. No.11/176,598 and U.S. Provisional Patent Application 61/482,598 filed onMay 4, 2011, now abandoned, each of which is incorporated by referenceherein in its entirety for all purposes, is depicted. This catheter (6)of FIG. 1B has some similarities with the manually-steerable catheter(1) of FIG. 1A in that it has pullwires (10) coupled to a control ringassociated distally with a more flexible section (8) configured to steeror bend when the pullwires (10) are tensioned in various configurations,as compared with a less steerable proximal portion (7) configured to bestiffer and more resistant to bending or steering. The depictedembodiment of the robotically-driven steerable catheter (6) comprisesproximal axles or spindles (9) configured to primarily interface notwith fingers or the hand, but with an electromechanical instrumentdriver configured to coordinate and drive, with the help of a computer,each of the spindles (9) to produce precise steering or bending movementof the catheter (6). The spindles (9) may be rotatably coupled to aproximal catheter structure (12) which may be configured to mount to anelectromechanical instrument driver apparatus, such as that described inthe aforementioned U.S. patent application Ser. No. 11/176,598, nowabandoned, and may be coupled to the elongate portion (13) of thecatheter (6).

Each of the embodiments depicted in FIGS. 1A and 1B may have a workinglumen (not shown) located, for example, down the central axis of thecatheter body, or may be without such a working lumen. If a workinglumen is formed by the catheter structure, it may extend directly outthe distal end of the catheter, or may be capped or blocked by thedistal tip of the catheter. It is useful in many procedures to haveprecise 3-dimensional information regarding the shape of such cathetersas well as the position of the distal tip the catheters or otherelongate instruments, such as those available from suppliers such as theEthicon Endosurgery division of Johnson & Johnson, or Intuitive SurgicalCorporation. The examples and illustrations that follow are made inreference to a robotically-steerable catheter such as that depicted inFIG. 1B, but as would be appreciated by one of ordinary skilled in theart having the benefit of this disclosure, the same principles may beapplied to other elongate instruments, such as the manually-steerablecatheter depicted in FIG. 1A, or other elongate instruments, highlyflexible or not, from suppliers such as the Ethicon Endosurgery divisionof Johnson & Johnson, Inc., or Intuitive Surgical, Inc.

Elongate instruments, such as the catheters described above, endoscopes,bronchoscopes, etc., may include various structures or features forintegrating and/or for supporting the requirements of a shape sensingfiber (e.g., a fiber optic shape sensor) and its associated algorithmsto obtain accurate shape and position measurements of the elongateinstrument, while maintaining the ability of the elongate instrument tobe accurately driven and articulated.

Examples of Shape Sensing Fibers

Various types of shape sensing fibers may be used with elongateinstruments to measure shape and position. It is well known that byapplying the Bragg equation (wavelength=2*d*sin(theta)) to detectwavelength changes in reflected light, elongation in a diffractiongrating pattern positioned longitudinally along a fiber or otherelongate structure may be be determined. Further, with knowledge ofthermal expansion properties of fibers or other structures which carry adiffraction grating pattern, temperature readings at the site of thediffraction grating may be calculated. “Fiberoptic Bragg grating”(“FBG”) sensors or components thereof, available from suppliers such asLuna Innovations, Inc., of Blacksburg, Va., Micron Optics, Inc., ofAtlanta, Ga., LxSix Photonics, Inc., of Quebec, Canada, and IbsenPhotonics AIS, of Denmark, have been used in various applications tomeasure strain in structures such as highway bridges and aircraft wings,and temperatures in structures such as supply cabinets.

The use of such technology in shapeable instruments is disclosed incommonly assigned U.S. patent application Ser. Nos. 11/690,116, nowabandoned; 11/176,598, now abandoned; 12/012,795, now abandoned;12/106,254, issued as U.S. Pat. No. 8,050,523 on Nov. 1, 2011;12/507,727now abandoned; 12/192,033, issued as U.S. Pat. No. 9,186,046on Nov. 17, 2015, 12/236,478, issued as U.S. Pat. No. 8,989,528 on Mar.24, 2015; and 12/837,440, issued as U.S. Pat. No. 8,780,339 on Jul. 15,2014. The entirety of each of the above applications is incorporated byreference herein.

In an alternative variation, a single mode optical fiber is drawn withslight imperfections that result in index of refraction variations alongthe fiber core. These variations result in a small amount of backscatterthat is called Rayleigh scatter. Changes in strain or temperature of theoptical fiber cause changes to the effective length of the opticalfiber. This change in the effective length results in variation orchange of the spatial position of the Rayleigh scatter points. Crosscorrelation techniques can measure this change in the Rayleighscattering and can extract information regarding the strain. Thesetechniques can include using optical frequency domain reflectometertechniques in a manner that is very similar to that associated with lowreflectivity fiber gratings. A more complete discussion of these methodscan be found in M. Froggatt and J. Moore, “High-spatial-resolutiondistributed strain measurement in optical fiber with Rayleigh scatter”,Applied Optics, Vol. 37, p. 1735, 1998 the entirety of which isincorporated by reference herein.

Methods and devices for calculating birefringence in an optical fiberbased on Rayleigh scatter as well as apparatus and methods for measuringstrain in an optical fiber using the spectral shift of Rayleigh scattercan be found in PCT Publication No. WO2006099056 filed on Mar. 9, 2006and U.S. Pat. No. 6,545,760 filed on Mar. 24, 2000 both of which areincorporated by reference herein. Birefringence can be used to measureaxial strain and/or temperature in a waveguide. Using Rayleigh scatterto determine birefringence rather than Bragg gratings offers severaladvantages. First, the cost of using Rayleigh scatter measurement isless than when using Bragg gratings. Rayleigh scatter measurementpermits birefringence measurements at every location in the fiber, notjust at predetermined locations. Since Bragg gratings require insertionat specific measurement points along a fiber, measurement of Rayleighscatter allows for many more measurement points. Also, the process ofphysically “writing” a Bragg grating into an optical fiber can be timeconsuming as well as compromises the strength and integrity of thefiber. Such drawbacks do not occur when using Rayleigh scattermeasurement.

Integration of Fibers in Steerable Catheters

When integrating a fiber into an elongate instrument, e.g., a manuallyor robotically steerable catheter, the distal end of the fiber and thedistal end of the instrument can be fixed relative to one another. Thisprovides for a reliable correlation between the shape of the fibersensor and the actual shape of the instrument. If the fiber does notreside within the neutral axis (axis in which path length does notchange during bending) of the elongate instrument (as is often the case)it can be beneficial to isolate the fiber from the axial strain of theinstrument. This can be achieved by decoupling the fiber and theinstrument (i.e., floating the fiber) along the length of theinstrument.

In one variation, as shown in FIG. 2A, one or more lumens 22 may bedefined through the elongate instrument 20 for receiving one or morefibers 24, such that a fiber 24 may be allowed to slide freely withinthe lumen 22 of the elongate instrument 20. By being allowed to slidefreely within a lumen 22 of the elongate instrument 20, the maximumstrain subjected to the fiber 24 will be reduced to levels low enoughfor the shape algorithms to process shape, strain, etc data. A freefloating fiber 24 may avoid being stretched or compressed during thebending or articulation of an elongate instrument 20. A slidable or freefloating fiber may allow the fiber to remain under the maximum allowablestrain of the fiber.

In certain variations, a support component, e.g., a tube (e.g.,polyimide), a liner (e.g., PTFE), coil, coil pipes, or braiding(polyimide) may be incorporated into or around any portion of a lumen ofan elongate instrument to maintain the patency or openness of the lumenand minimize friction such that a fiber can slide freely or float withinthe lumen of the elongate instrument, or to provide reliable positioningof the lumen within the elongate instrument, or to reinforce a lumen.Such support components may hold a lumen open and prevent collapse ofthe lumen during articulation of the elongate instrument to avoidbinding or pinching of the fibers. Such support components may beincorporated into an articulation section of an elongate instrument,along the entire length of the catheter, or along other various sectionsalong the length of the catheter. For example, FIGS. 2A-2B show one ormore lumens 22 in an elongate instrument 20 having a coil 26 positionedtherein, e.g., positioned coaxially with the lumen to surround a fiberpositioned within the lumen of the coil. Fibers may be positioned withina lumen of certain support components, such as a tube, coil or coilpipe, positioned within the lumen of the elongate instrument. In oneexample, the support component may include an expanded coil or coil pipepositioned in a distal articulation section of the elongate instrumentand a braid or polyimide braid may be positioned in a proximal sectionor other portion of the elongate instrument.

FIG. 5 illustrates a variation of an elongate instrument 200 wherein adistal section 50 of the elongate instrument includes a first fiberlumen 52 and a proximal section 55 of the elongate instrument 200includes a second fiber lumen 58, e.g., axially aligned with the firstfiber lumen 52. Both fiber lumens 52, 58 can be integrated into the wallof the elongate instrument 200 leaving an open center working lumen 54in the elongate instrument 200. Additionally, control wire lumens (notshown) may be integrated into the elongate instrument wall running froma proximal end of the elongate instrument 200 to a distal end. In somecases, in order to controllably and reliably articulate the elongateinstrument 200 it can be desirable to construct the elongate instrumentdistal section 50, e.g., a distal articulation section, such that is haslower axial stiffness than the proximal section 55. The following willdescribe a variation of a construction that will provide such aconfiguration while providing for open fiber lumens 52, 58 which mayinclude low-friction bearing surfaces for contact with a fiber.

FIGS. 5A-5B illustrate a magnified cross section of the distal section50 of the elongate instrument 200 showing the center lumen 54 and thefirst fiber lumen 52 as well as a coil, e.g. a coil pipe 51 or expandedcoil pipe, and a fiber 53 positioned within the coil pipe 51. As shownin FIG. 5, the coil pipe 51 can be positioned inside the first fiberlumen 52 in the wall of the distal section 50 of the elongateinstrument. In this variation, the coil pipe 51 may have an open pitchand may be fixed at its distal and proximal ends to the elongateinstrument 200 such that the coil pipe 51 is free to float or extendand/or compress within the first fiber lumen 52. The coil pipe 51 mayhave a thin wall thickness, and/or a low axial stiffness. The firstfiber lumen 52 surrounding the coil pipe 51 may be composed of anelastomer, e.g., Polyether Block Amide (PEBAX®). The coil pipe-in-lumenconstruct, while low in axial and bending stiffness, allowing the distalsection of the elongate instrument to remain flexible, has high hoopstrength and holds the first fiber lumen 52 open during bending. Byallowing the coil pipe 51 to float instead of embedding it in the wallof the elongate instrument 200, the coil pipe 51 separates the fiber 53from the first fiber lumen wall. The fiber 53 is in direct contact withthe coil pipe, which may be made from a metal or similar material, andany friction between the fiber and the coil would be less than thefriction between the fiber and the lumen wall if the fiber were incontact with the lumen wall. This allows the coil pipe 51 positionedwithin the first fiber lumen 52 to provide a low-friction bearingsurface for contact with the inner fiber 53.

The coil pipe 51 provides one mechanism for floating a fiber 53 inside alumen 52 that undergoes bending strain such that: the lumen 52 remainspatent (open) under bending strain; the fiber 53 to lumen 52 wallinterface remains low in friction under bending strain; and/or theaddition of the coil or mechanism does not contribute significantly tothe overall axial and bending stiffness of the elongate instrument 200.

While the coil or coil pipe 51 is illustrated in FIGS. 5, 5A, and 5B asbeing integrated into the distal section 50 of the elongate instrument200, it should be understood that the coil or coil pipe 51 could extendinto any length of the proximal section 55 of the elongate instrument200 or the entire length or substantially entire length of the elongateinstrument 200. The coil pipe 51 could be fixed at its distal end to theelongate instrument 200 and/or at its proximal end to the elongateinstrument, or could be allowed to be completely free floating within aclosed lumen in the elongate instrument 200.

Expanded coil pipes may vary in size. For example, expanded coil pipeshaving a diameter ranging from about 1-2 mm or mils may be used in anelongate instrument where space constraints are an issue. Depending onthe desired stiffness of the elongate instrument, coil pipe stiffnessmay be reduced by stretching the coil pipe so that tensile andcompression stiffness of the coil pipe is decreased below that of othercomponents of the elongate instrument. This reduces the effects of anypotential increased bending stiffness or non-uniform bending stiffnessthat may be caused by the addition of a coil pipe to the elongateinstrument.

FIGS. 5C-5D each illustrates a cross section of the proximal section 55of the elongate instrument 200 having the second fiber lumen 58incorporated into a braid 56 of or in a wall 57 of the elongateinstrument 200. Additionally, a set of control wire lumens 60 and thecenter lumen 54 are provided. In this variation, the second fiber lumen58 with high hoop strength can be made of polyimide or a similarmaterial providing higher stiffness than PEBAX or other material used tomake the first fiber lumen 52, allowing for higher stiffness in theproximal section 55 of the elongate instrument 200 compared to thedistal section, if desired. The second fiber lumen 58 along with thecontrol wire lumens 60, and the center lumen 54 may be incorporated intothe braid 56 of the elongate instrument 200 or elongate instrument orshaft wall 57. This braid 56 may be encapsulated with a soft polymer,e.g., PEBAX.

FIG. 5C illustrates a variation of a braid pattern which can be used tosecure lumens, including the second fiber lumen 58, the center lumen 54,and control wire lumens 60. In this variation, one layer of braid 56 canbe laid underneath the control wire lumens 60 and the second fiber lumen58 surrounding the center lumen 54 while another layer of braid 56 canbe laid over the control wire lumens 60 and the second fiber lumen 58.

FIG. 5D illustrates an alternative variation of a braid pattern. Thesecond fiber lumen 58 and control wire lumens 60 are braided into thecatheter wall with multiple layers of braid 56 a and 56 b, which crossand/or wind around each lumen 58, 60. In one variation, a layer of braid56 a may wind around the outer diameter of the second fiber lumen 58,between the control wire lumens 60 and the center lumen 54. Anotherlayer of braid 56 b may be wound, e.g., simultaneously, in the oppositedirection as the braid 56 a, around the outer diameters of the controlwire lumens 60 but winding close to the center lumen 54 between eachcontrol wire lumen 60. The braid 56 b winds between the second fiberlumen 58 and the center lumen 54. The braid pattern creates a diamondlike pattern on or in the elongate instrument when viewed from a sideview (not shown).

The braid pattern of FIG. 50 holds the second fiber lumen 58 in a fixedor substantially fixed radial position throughout the length or at leasta portion of the length of the elongate instrument or the shaft of theelongate instrument 200, allowing for a reliable correlation between theshape and orientation of the fiber 59, positioned in the second fiberlumen 58, and the elongate instrument's shape and orientation.Additionally, the braid pattern of FIG. 50 provides for a smaller,compact cross sectional area of the elongate instrument compared to theprevious braid shown in FIG. 5C. The encapsulated braid 56 and lumen 58construct provides good kink resistance such that the fiber 59,positioned in the lumen 58, is not impinged on or such that anyimpingement is minimal. The fiber lumen 58 remains close to the centerlumen 54 under one or more or all bending configurations such that thefiber 59 assumes the same shape or substantially the same shape of theelongate instrument 200 or the shaft of the elongate instrument 200. Anyof the braids described therein may be positioned in any portion of theproximal or distal sections of the elongate instrument or along theentire length or substantially entire length of the elongate instrument.

The braid 56 and lumen 58 construct provides a mechanism or allows for amethod for incorporating or integrating a fiber 59 in the wall of anelongate instrument 200 or shaft of the elongate instrument 200, suchthat: the fiber 59 is provided with an accurate and reliable radialpositioning within the elongate instrument and has minimal twist; thefiber 59 assumes the same shape or substantially the same shape of theelongate instrument during elongate instrument bending; and/or the fiber59 is free to float and is not impinged or minimally impinged duringelongate instrument bending.

Tubes, liners, pipes or other support components may be incorporatedinto an elongate instrument in a symmetrical and balanced configuration.For example, tubes having 90 degree symmetry may be arranged in anelongate instrument to maintain uniform bending stiffness and provideease in manufacturing.

In certain variations, where shape sensing fibers are incorporated intoan elongate instrument in an unbalanced or nonsymmetrical configuration,additional fibers or “dummy fibers” may be introduced into the elongateinstrument to create a more symmetric and uniform elongate instrumentstructure. Additional or “dummy” fibers may be added to the articulationor other section of the elongate instrument and they may be freefloating.

FIG. 2B shows an elongate instrument 20 having a symmetrical arrangementof lumens 22. One or more shape sensing fibers 24 and “dummy fibers” areincluded in the lumens 22 of the elongate instrument 20. Optionally,additional fibers for providing a balanced and symmetric configurationcould be shape sensing fibers. The additional shape sensing fibers mayprovide multiple sensing of the same shape and position, which may beused to reduce any error in shape sensing.

A free floating fiber may contribute negligible bending stiffness to anelongate instrument while providing no or minimal friction or bindingbetween the fiber and lumen of the elongate instrument. Variouscoatings, e.g., polyimide coatings or other friction reducing compoundssuch as silicones and other lubrication, may be applied to lumens orfibers to reduce friction between a fiber and lumen. A polyimide coatingmay also reduce the overall diameter of a fiber so that the fiber may beeasily fit into a wall of an elongate instrument, such as a Hansenvascular catheter NORTHSTAR™ which has been described in previouslyincorporated applications.

Various mechanical structures and materials, such as those discussedsupra, may be incorporated into an elongate instrument to avoid orreduce twist of the elongate instrument out of an articulation planeand/or to maintain a longitudinally uniform bending stiffness through anarticulation section of the elongate instrument so that there is aconstant or consistent radius of curvature in the articulation section.Indeed, various structures and/or materials may be introduced into anelongate instrument to stiffen various parts of the elongate instrumentto avoid or reduce twist and to maintain uniform bending stiffness.

Lumens in an elongate instrument may be spaced apart from control wiresin any number of degrees or configurations. For example, referring backto FIG. 2B, the fiber lumens 22 are spaced apart from the control wires26 by 45 degrees.

FIGS. 3A-3C show examples of elongate instruments 30 where the fiber 34and fiber lumen 32 are placed at various positions at various degrees inrelation to control wire 36.

FIGS. 4A-4C show examples of elongate instruments 40 having varyingnumbers of control wires 46 with fiber 44 positioned in a fiber lumen42, located in various positions in relation to the control wires 46.

In certain variations, an elongate instrument may have any combinationof one or more control wires and one or more fibers. Any number oflumens of an elongate instrument may be populated with control wiresand/or fibers and/or support components. For example, an elongateinstrument having four lumens may have three lumens populated withcontrol wires and one populated with a fiber. In certain variations, oneor more fibers may be positioned in one or more lumens in a wall of anelongate instrument; for example, around the circumference of theelongate instrument. In other variations, one or more fibers may bepositioned along a neutral axis of an elongate instrument, (e.g., alongthe center axis of the elongate instrument or the axis in which pathlength does not change or has negligible change during bending). Inother variations, one or more fibers may be positioned along the outsideof an elongate instrument. The fiber may be integrated into an elongateinstrument in a manner such that it does not exceed the maximum straintolerability of the fiber.

In certain variations, an elongate instrument may include a distal tip,distal end or other structures or materials configured to support atleast a portion of a fiber distal end or fiber termination.

A distal tip of a fiber may include a termination attached thereto.FIGS. 6A and 6B (a cross sectional view) show one variation of a fiberdistal end 65 integrated within an elongate instrument distal tip 61. Atermination 67 is spliced at junction 68 onto the fiber distal end 65.The termination 67 may be made from a variety of materials having lightabsorptive properties, such that light travels into the termination 67and fiber 65 and back reflection is reduced or eliminated (e.g., suchthat reflection does not disrupt shape sensing algorithms). For example,the termination 67 may be a piece of glass which is highly absorptive.The termination 67 may range in length, e.g., from about 1-3 mm. Thetermination 67 may have a diameter similar in size to the fiber 65itself such that the termination 67 may be attached to the fiber 65 andloaded through a lumen of the elongate instrument along with the fiber65.

Because the junction 68, joint, or splice area where the termination 67is spliced onto the fiber distal end 65 may be weak or fragile, theelongate instrument may include a distal tip 61 or other structure ormaterial to protect the junction 68, termination 67 and/or fiber distalend 65. The fiber termination 67 and/or junction 68 may be placed in theelongate instrument in a position or section that bends or articulatesminimally or in a reduced manner and/or may be protected by the elongateinstrument or other structure so that the termination 67 and/or junction68 don't bend or have minimal bending, and are protected duringarticulation and use of the elongate instrument, e.g., when the elongateinstrument is contacting or ramming into tissue or other structures.

The elongate instrument tip 61 may include a control ring 69 used toterminate control or pull wires at the distal tip of the elongateinstrument as previously described. The control ring 69 may be notchedand may allow the fiber 65 to extend along the control ring 69 and intothe tip 61. The tip 61 and/or control ring 69 may include stainlessstill, nylon, or other materials that provide stiffness to the tip 61and control ring 69 sufficient to support the termination 67 and reduceor eliminate lateral bending of the termination 67. Nylon may be meltedonto the termination 67 to fix the fiber 65 and/or termination 67 to thedistal end or tip 61 of the elongate instrument. The elongate instrumenttip 61 may include a stiff or rigid section, e.g., about 2-3 mm inlength, that is strong enough to house the splice/junction 68 andtermination 67 and prevent them from being loaded with too much strainor strain beyond the maximum strain tolerability of the splice/junction68, fiber distal end 65, or termination 67 portions. In certainvariations stiff materials, such as Nylon or PEBAX 72D may be meltedover the junction, termination and/or fiber, e.g., as shown in FIGS.6A-B.

In certain variations various features that may reduce or eliminatebreaking or bending of a fiber termination include the following. Theelongate instrument tip may include a clear portion, made from a clearsubstance, e.g., clear nylon, that allows for visibility of the fiberthrough the wall of the elongate instrument tip. This helps preservealignment or align the fiber and/or termination within the elongateinstrument tip, during the fixing of the fiber and/or termination to theelongate instrument, e.g., during nylon or other material melt down. Thestiff section of the elongate instrument tip, e.g., a stiff nylonsection, may be increased or decreased in length to provide a lengthsufficient to protect the termination. A stiff or rigid sleeve, sheath,tube or cover, (e.g., made from 72D PEBAX, stainless steel, nylon, orpolycarbonate) may be positioned or melted over at least portion of thedistal section or tip of the elongate instrument, the stiff section of aspine, or the control ring to increase overall stiffness of the elongateinstrument tip.

In certain variations, a rigid tube (e.g., stainless steel, nylon, orpolycarbonate) may be positioned over the termination to protect thetermination. The termination may be glued or otherwise fixed in a rigidtube which may be small enough to slide through a lumen of the elongateinstrument. The termination and/or fiber and rigid tube may be slidthrough the lumen and fixed to the elongate instrument tip or to a nylontip. Alternatively, the rigid tube may be integrated into the elongateinstrument tip or control ring and the fiber and/or termination may beslid through the lumen of the elongate instrument and through the rigidtube and fixed to the elongate instrument by gluing or melting materialsaround the fiber. The length of the control ring may be modified orincreased as necessary to extend beyond the termination to increase thelength of the stiff section at the distal end or tip of the elongateinstrument to protect the termination. Optionally a spine (e.g., nitinolspine) in the articulation section of the elongate instrument may be cutor designed such that at least a portion of the spine protects thetermination and/or stiffens the elongate instrument. Optionally, stiffmaterial, e.g., nylon, may be melted over the termination and/orjunction section of the fiber for protection and to reduce strain. Theelongate instrument tip or a feature attached to the termination or thetermination may be designed in a variety of shapes, e.g., square,triangle, or have modified geometric features to provide strength.

In another variation, the elongate instrument tip may include lightabsorbing material (e.g., black materials such as black nylon) which maybe positioned around the termination to reduce reflections at the tip ofthe fiber and elongate instrument. The light absorbing materials andother structures positioned in the elongate instrument or at the tip ofthe elongate instrument may improve or aid the optical propertiesrequired for fiber optic shape sensing.

In another variation, the fiber termination or junction may be coatedand/or encapsulated to provide protection from fluid, water vapor, orvapor ingress. The distal end of a fiber, junction or the terminationmay be protected from moisture ingress in order to preserve the fiber'soptical qualities. This may be accomplished by coating the terminationand any fiber portion that may be stripped or spliced for attachment ofthe termination to the fiber with a coating material. Suitable coatingmaterials may be thin to maintain the fiber diameter size at a size thatis smaller than the size of the lumen in the elongate instrument inwhich the fiber may be positioned. The coating materials may also beconformal and able to resist or keep out moisture from the fiber. Suchmaterials include, for example, polyimide dip/vapor deposition, parylenevapor deposition, urethane, and silicon. The fiber may be dip coatedbefore insertion into a lumen. Encapsulation material could also beinjected or melted from the open end of the lumen before an elongateinstrument or catheter is tipped and the lumen end is sealed.

In certain variations an off the shelf fiber can be integrated into anelongate instrument, such as a catheter. The off the shelf fiber caninclude a bare fiber with a polyimide coating along the length of thefiber and a termination at its distal tip. The off the shelf fiber maybe prepared to fulfill shape sensing requirements before or duringintegration of the fiber into an elongate instrument.

As shown in FIG. 7, which illustrates a variation of a fiber assembly 70prior to integration within a catheter assembly, the fiber assembly mayinclude various accessories or elements for fulfilling shape sensingrequirements. A section 71 located near a proximal end of the off theshelf fiber 76 may be placed in a well toleranced straight track,hypotube or silica block or tube to provide a straight section 71. Thestraight section 71 may vary in length, e.g., the section may be about 2to 4 cm long. The straight section 71 may be used to initializealgorithms. A strain relief 72 and/or jacket may be provided over aportion of the off the shelf fiber 76 proximal to the straight section71. In certain variations, the strain relief 72 is provided at aproximal end of an off the shelf fiber 76, e.g., where the fiber exitsan elongate instrument, providing a gradual exit of the fiber 76 fromthe elongate instrument. A polyimide tube 73 is provided at a distal endof a fiber 76. In one example, the polyimide tube may be continuous orextend to the proximal end of the fiber and act as the strain relief.Protective tubing 74 and/or a connector 75 may be placed on the mostproximal end of the off the shelf fiber 76.

A fiber has a minimum bend radius and may be fragile. As such, it may bedesirable to minimize the number of fiber preparation steps performedafter the fiber is incorporated or integrated into a catheter orelongate instrument. For example, preparation of the fiber's proximalend may be performed before integration of the fiber into the catheter.Calibration of a fiber may be performed before a pull tube is glued oraffixed to a fiber or before the fiber is integrated or incorporatedinto a catheter or other elongate instrument.

Various processes and methods for integrating a fiber into an elongateinstrument, such as a catheter, are described herein.

In alternative variations, a method or process for integrating orincorporating a fiber into a catheter may include the following. Toavoid pushing the fragile fiber termination or section through the lumenof a catheter, the termination section of the fiber assembly may beaffixed or glued into a long pull tube, e.g., a long polyimide pull tube75 as illustrated in FIG. 7. The pull tube may be constructed forexample from a polyimide tube or tube made from another similarmaterial. Optionally, the pull tube may include a mandrel to stiffen thetube for pushing. The pull tube which is fixably coupled to the fiber isthen pushed from the proximal end of the catheter through one of thecatheter lumens to the distal end of the catheter. Once the pull tube ispushed far enough through the lumen so that it protrudes past the distaltip of the catheter, the pull tube may be pulled from the distal enduntil the fiber can be positioned as desired. In one variation thetermination junction on the fiber assembly can be positioned in themiddle of the control ring. The pull tube can then be cut off of thefiber assembly, and the termination can be melted and embedded into thecatheter tip with Pebax or comparable materials in the same mannerpreviously described.

Alternate materials and constructions may be utilized for a pull tube.In one variation the fiber assembly termination can be affixed tomandril which can be glued in a shorter pull tube. In another variation,the fiber assembly termination may be affixed or glued inside astainless steel tube (e.g., the tube being about 3-6 mm in length). Apull tube and/or wire may then be affixed or glued to the stainlesssteel tube and the pull tube or wire is then pushed or pulled through alumen of the catheter.

FIGS. 8A-D show a variation of a process or method for integrating afiber assembly such as that illustrated in FIG. 7 into an elongateinstrument or elongate instrument assembly, such as a robotic catheterassembly. FIGS. 8A-8D shows a robotic catheter assembly 80 having acatheter 81 with a lumen 84 for a fiber, a splayer assembly 82, pulleys83 and a registration fixture 86, e.g., a shape plate or service loopplate, attached to the splayer 82. The catheter 81 can include controlwires fixed near the distal tip of the catheter to a control ring andadditional lumens such as working lumens. The catheter 81 can be coupledto the splayer assembly 82 which contains pulleys or spindles thatactuate the control wires which run from the splayer 82 to the distaltip 87 of the catheter 81 as described in detail in previouslyincorporated patent applications. Coupled to the splayer 82 is aregistration fixture configured with a groove for receiving a serviceloop. The registration fixture can be sealed with a fixture lid. Incertain variations, registration fixtures may be designed to prevent afiber from bending below its minimum bend radius. A registration fixturemay also be designed to hold, accommodate or provide a service loopalong the fiber.

Providing a fiber with extra length or a service loop (e.g., the serviceloop may have a length of about 1-2 cm or longer) is one mechanism forabsorbing a length change in the fiber when the fiber is positioned offof the neutral axis of an elongate instrument. For example, a fiberlength change may occur when a catheter, and the fiber integratedtherein, is bent or articulated in various degrees of freedom. If afiber is anchored to an elongate instrument off the neutral or centeraxis of the elongate instrument, as the elongate instrument is bent, thefiber may take a different path than the elongate instrument. A serviceloop may accommodate a fiber length change due to axial compression orbending of the elongate instrument or due to manufacturing tolerances ofthe elongate instrument. A service loop may provide the fiber with extralength such that the fiber may slide in and out of the elongateinstrument, as the service loop absorbs the length change. As anelongate instrument bends, the path length of the fiber may change andthe amount of fiber present within the elongate instrument may change. Aservice loop may absorb these length changes. A service loop may allowan elongate instrument to be bent without adding strain to an integratedfiber, e.g., integrated in the walls of the elongate instrument. Aservice loop may allow a fiber to lengthen or contract within anelongate instrument without exceeding its minimum bend radius. A serviceloop may have various shapes and configurations and may be positionedanywhere along a fiber, e.g., anywhere along a fiber between a fixeddistal section of the fiber (e.g., fixed to a distal section of anelongate instrument) and/or a fixed proximal section of the fiber (e.g.,fixed to a proximal section of an elongate instrument or other structureassociated with the elongate instrument). A service loop may be freefloating and/or positioned in a groove or track or on a surface of aregistration fixture.

In certain variations, a registration fixture may be positioned in aknown orientation including but not limited to vertically orhorizontally relative to a splayer or other structure associated with acatheter and the registration fixture may have a variety of shapes andconfigurations. The registration fixture may include a groove or trackhaving a variety of shapes for receiving a fiber or service loop of thefiber. The groove or track may allow the service loop to spiral in theleft hand or right hand direction or take on a configuration or shapesimilar to a bird's eye, a jog shape or other curve.

Various examples of registration fixtures are described herein. However,a registration fixture may be any structure on which or within which afiber, elongate instrument, splayer or other structure may bepositioned, coupled to, affixed to or otherwise held in various known orunknown configurations to register the coordinate system of a fiber withthe coordinate system of an elongate instrument, splayer or otherstructure. In certain variations, in use, a register fixture may belocated or positioned in any orientation or configuration (e.g.,parallel or perpendicular) relative to an elongate instrument, splayeror other structure. In certain variations, the location of theregistration fixture relative to the elongate instrument or structure ofinterest may be known. A registration fixture may or may not be attachedor coupled to an elongate instrument. In certain variations, theregistration fixture may be attached to a splayer or it may not beattached to an elongate instrument, e.g., a fixture used for in-factoryregistration or calibration.

Various registration fixtures are described herein.

FIGS. 9A-9B show one example of a registration plate 90 having a groove91 for positioning a fiber 92 (e.g., a service loop of a fiber), wherethe registration plate 90 is positioned horizontal to the splayer 93 inan out of plane splayer configuration.

FIG. 10A-10B show variations of registration plates for positioning afiber in various shapes or configurations.

FIG. 10A shows one example of a plate 100 having a groove 101 forpositioning a service loop 103 of a fiber 102 in a bird's eye shape.FIG. 10B shows one example of a registration plate 110 having a groove111 for positioning a service loop 113 of a fiber 112 in a loop shape.FIG. 10C shows one example of a registration plate 126 having a groove121 for positioning a service loop 123 of a fiber 122 in a jog shape.

Steps for manufacturing a catheter and integrating the fiber into thecatheter assembly as shown in FIG. 8A will now be described. It shouldbe noted that alternative and additional steps which may be utilizedhave been described in detail in applications previously incorporated byreference which are not included herein for clarity. Initially thecatheter can be manufactured with methods either well known in the artor previously described providing several lumens including but notlimited to the fiber lumen, the working lumen, and lumens for thecontrol wires with the control wires installed and affixed to a controlring near the distal tip of the catheter. Nylon, PEBAX or other similarmaterials may be melted on the distal tip of the catheter to create asoft tip. The fiber lumen can be kept open or patent when the softdistal tip is created. The catheter can then be coated and the cathetercontrol wires can be installed onto the splayer spindles. Theregistration plate can be installed onto the splayer with theregistration plate removed to prepare for fiber assembly integration.

FIG. 15 shows, another variation of a registration fixture 186 forreceiving fiber slack or a service loop 188. The registration fixture186 may be in the form of a plate having a track 187 that guides thefiber 182 from the proximal end of the catheter 181 (without exceedingthe minimum bend radius) into a service loop 188 that allows the fiber182 to have some predetermined amount of travel. The registrationfixture 186 may be fixed to a splayer 183. Because it can be difficultto consistently fix the fiber length during integration of the fiber 182within the registration fixture 186, the proximal end of the fiber 182can be fixed to an anchor slide 189 which can be a block or otherstructure made from silica, quartz, glass or other similar material. Theanchor slide 189 may reside or be positioned in a pocket 183 on theregistration fixture 186, such that the anchor slide 189 is capable ofbeing slid back and forth within the pocket 183 during installation toaccommodate different lengths of fiber 182. The anchor slide 189 and thepocket 183 may be configured in rectangular shapes and can be sized suchthat the anchor slide 189 is prevented from any vertical, yaw, or pitchmovement while still providing axial movement. In certain variations,during integration, the anchor slide 189 may be positioned within thepocket 183 to fix a desired length of the fiber 182, and then glued intoposition. Proximal to the fiber anchor slide 189 may be a strain relief190 leading out of the fixture 186 which provides strain relief andprotection for the fiber 182 until it reaches the next component.

The registration fixture 186 provides a method or mechanism for managingfiber slack at a proximal end of catheter; such that: the minimum bendradius of the fiber is not exceeded; the fiber is fixed on the proximalend, floating on the distal end, and the fiber is allowed to travel somepredetermined distance; the fiber is supported after exiting theproximal end; the fiber is held in some position that allows for shaperegistration; and/or the proximal end anchor of the fiber can beadjusted to accommodate for tolerance stack up.

FIGS. 8B-8D illustrate one variation of a method of integrating a fiberassembly 85 (e.g., similar to the fiber assembly shown in FIG. 7), intothe catheter assembly 80 illustrated in FIG. 8A. Before the fiberassembly 85 is slid or inserted into the catheter fiber lumen, thedistal tip or termination of the fiber assembly 85 may be affixed to apull tube as previously described. As shown in FIG. 8B, the pull tubeattached to the fiber assembly 85 may be fed through the registrationfixture and the fiber assembly 85 can then be inserted into the proximalend of the catheter fiber lumen 84, pulled through the fiber lumen 84 ofthe catheter, and pulled through the catheter distal tip 87 in the samemanner previously described. As shown in FIG. 8C, any excess polyimidepull tube is cut off and nylon may be melted down to secure the fiber 85to the catheter 81. PEBAX may be shaped on to the catheter to form asoft tip. As shown in FIG. 8D, on the proximal splayer side of the fiber85, the fiber 85 may be wrapped into a service loop 88 and theprotective tube 74 or polyimide and/or strain relief 72 sections on thefiber may be affixed or glued into place, e.g., on the registrationfixture 86 allowing the fiber 85 to remain free to float or slide withinthe catheter fiber lumen. The registration fixture 86 may then be closedand secured once the fiber 85 is in place. In certain variations, aconnector 75 used with the fiber may be pigtailed or incorporated intothe splayer or may remain bare.

In another variation, a pull tube may not be necessary if the fibertermination can become more robust due to a change in materials,providing a pushable termination. The fiber assembly can remain bare andcan be installed without the use of a pull tube. For the bare fiberassembly, a lid, cap, or short tube may be placed over the fiber distalend or termination to protect the termination during installation of thefiber assembly into the catheter assembly. In another example, atermination of attenuative glass may be fused to a fiber tip. Thefiber/glass termination may be dip coated in a thin layer of polyimide.If the fiber is fixtured or positioned such that it is straight and doesnot collide forcefully with other components in the catheter, the fibermay be pushed through the catheter and embedded in nylon or anothersupport structure, such as those described for the pullable termination,at the tip of the catheter

A variation of a method for integrating a shape sensing fiber in anelongate instrument may include inserting the fiber into a lumen of theelongate instrument, wherein the elongate instrument has a supportcomponent positioned therein for maintaining patency of the lumen duringarticulation of the elongate instrument; and fixing a distal end of thefiber at a distal end of the elongate instrument, wherein the fiberremains free to slide or float within the lumen of the elongateinstrument.

FIG. 16 shows a flow chart for one variation of a method of integratinga fiber into an elongate instrument. Referring to FIG. 16 (and FIG. 15which illustrates the proximal end of the catheter 181 and fiber 182), avariation of a process for integrating the fiber 182 into the catheter181 is shown including one or more of the following steps. A cathetershaft 181 is made having an open fiber lumen for the fiber 182 in amanner as previously described. The catheter 181 is integrated into thesplayer 183 also as previously described. The fiber 182, e.g., an offthe shelf fiber, is prepared by fixing or gluing the proximal end of thefiber 182 to the anchor slide 189. The distal end of the fiber (notshown) can then be slid into the fiber lumen from the proximal end ofthe catheter 181 and pushed until the distal tip of the fiber 182reaches a distal section of the catheter 181. The anchor slide 189 onthe proximal end of the fiber 182 remains outside the proximal end ofthe catheter 181 near the splayer 183. With the anchor slide 189positioned in a correct orientation using for example a fixture (notshown) which holds the anchor slide 189 in a fixed position, the fiber182 is dithered or slid in a back and forth motion within the fiberlumen to break any friction between the fiber 182 and the fiber lumenwall, allowing the fiber 182 to resolve any twist it may have incurredduring insert into the fiber lumen. The distal tip of the fiber 182 canthen be properly aligned with respect to the catheter 181, e.g., thetermination junction is positioned in the middle of a control ring andPebax 72D, 55D, and 35D (or like materials) are melted onto the distalend of the catheter 181 to form a soft tip at the distal end of thecatheter 181. Alternatively or additionally, nylon may be melted to thetermination to secure the termination to the catheter tip. This processresults in the distal end of the fiber 182, including the entiretermination, being embedded inside the catheter tip.

A verification that the fiber 182 is not twisted can then be performedby either placing the catheter 181 in a known position and monitoringshape data from the fiber 182 to ensure the readings are accurate or byusing a fixture to ensure no fiber twist. The proximal section of thefiber 182 which protrudes from the proximal end of the catheter 181 canthen be placed into the service loop 188 in the registration fixture 186and the anchor slide 189 on the proximal end of the fiber 182 can beplaced into the pocket 184 of the registration fixture 186. Theanchoring slide 189 is free to slide in the axial direction of the fiber182 within the pocket 184. Thus anchoring slide 189 is adjusted withinthe pocket 184 until the desired fiber slack within the service loop 188is obtained. Once in a desired position, the anchor slide 189 can befixed, for example glued into place. A cover can be placed on theregistration fixture 186 to protect and secure the fiber 182 within theservice loop 188 and pocket 184.

In another variation, the fiber lumen at the distal control ring can beskived away such that the fiber is clearly visible once inserted. Outerplastic material that has flowed over the control ring can be cut awayvisually exposing the fiber. This method can allow the fiber to bealigned more accurately. Once aligned, a small amount of fast-curingadhesive can be applied to fill up the skive and provide a rigid,protective, encapsulation around the fiber termination. Variousdurometers of PEBAX, including but not limited to PEBAX 72D, 55D, and35D, can then be melted onto the distal end of the catheter to form thecatheter soft tip fully embedding and securing the fiber terminationwithin the catheter tip. The fast curing adhesive bond can allow thecatheter and fiber assembly to be handled before forming the cathetertip without the risk of misaligning the fiber. Indeed, a catheter orother elongate instrument tip may be encapsulated with PEBAX or othersimilar material.

In any of the variations described herein, fixturing or jigging may bebuilt to more precisely align the termination splice or junction with asupport structure in the catheter tip. Accurate or precise alignment maybe important because the splice or junction may be more delicate andfragile than the surrounding structures, e.g., the fiber itself or thetermination, e.g., made from glass.

In another variation, a fiber may be incorporated or integrated into acatheter before splayering is performed. The fiber may be placed in aprotective enclosure during the final steps of the process and/orsplayering.

In other variations, other mechanisms may be provided for eliminatingthe effects of differing strains on varying surfaces of a fiber. Theseother mechanisms may or may not involve the use of a service loop. Inone variation shown in FIGS. 17A-17B, a fiber 204 m be wrapped around anelongate instrument 202, spiraling the fiber 204 around the elongateinstrument 202 such that the differing strains or bends on the inside oroutside or different surfaces of the fiber 204 cancel each other out.FIG. 17A displays the elongate instrument 202 in a straightconfiguration and 17B displays the elongate instrument 202 in a bentconfiguration. In this variation, the fiber 204 can be wrapped aroundthe elongate instrument 202 over a proximal section 210 and then fedinto a coil lumen 208 in a distal section 212. Sliding or floating thefiber within the elongate instrument may or may not be performed in sucha variation.

In another variation, a fiber may be positioned along the neutralbending axis of a elongate instrument, e.g., a catheter, bronchoscope,or endoscope. The neutral bending axis an imaginary line that runsthrough any structure, which is not subjected to strain when thestructure is subjected to a bend along its length. Since the neutralaxis is not axially strained during bending, any material, for example afiber, that is positioned along this line will not compress or expandduring the bending of the structure. Thus positioning a fiber along theneutral bending axis of an elongate instrument would minimize the amountof strain experienced by the fiber. The fiber may be glued, imbedded oraffixed to the elongate instrument along the neutral axis while avoidingbreakage due to bending because of minima strain experienced by thefiber along the neutral axis. In certain variations, a fiber may bepositioned or integrated anywhere within or on a surface of an elongateinstrument. For example, a fiber may be positioned along a neutralbending axis of an elongate instrument, within a wall of an elongateinstrument or on an outer surface of an elongate instrument. Floatingthe fiber and providing a service loop may or may not be required.

In another variation, the neutral bending axis of an elongate instrumentmay be altered by modifying the structure of the elongate instrument.For example, the neutral bending axis of the elongate instrument may bemechanically shifted to coincide with the center of the fiber. Anelongate instrument, such as a catheter, may be constructed in such away that the neutral bending axis of the shaft is not directly along thecenter of the catheter cross section. The neutral bending axis of acatheter may be shifted by intentionally adding a single or a series ofaxially stiff components, e.g., a hypodermic tube, along the length ofthe catheter or by integrating such components into a wall of thecatheter. The inclusion of these stiff members will govern the locationof the shaft's neutral bending axis and shift it relative to thestructure's cross section center. The catheter may or may not have acentral working lumen.

In one variation, in order to minimize or eliminate the strain appliedto a shape sensing fiber, an axially stiff lumen, such as a hypodermictube, may be incorporated into an elongate instrument or catheter shaft.This stiff lumen will now govern the neutral axis of the structure. Ifthe fiber resides inside this lumen, it can be concluded that the fiberwill not be subjected to any axial strain due to the bending of thestructure. This fiber integration approach will allow for the fiber tonot need a service loop at the proximal end of the catheter since itwill not need to compensate for its overall length inside the catheter.

In certain variations, an elongate instrument configured to support theintegration of a shape sensing fiber therein may be provided. Theelongate instrument may include a central working lumen, a fiber lumenpositioned along the neutral axis of bending of the elongate instrument,and one or more axially stiff components integrated in a wall of theelongate instrument. The axially stiff component may be in the form of ahypodermic tube. Optionally, the elongate instrument may not include acentral working lumen.

Registration of a Fiber Integrated in an Elongate Instrument

Various mechanisms and methods for registering a fiber to an elongateinstrument, to a splayer, component, fixture, or other structure whichmay or may not be coupled to or associated with an elongate instrument,or to other structures or devices are provided herein. In registration,the objective is to relate the coordinate system of the fiber to thecoordinate system of the instrument of interest; this involves relatingthe x, y, z, position and orientation of the two coordinate system (all6 degrees of freedom). Registration may involve the use of certainmechanical registration structures (e.g., structures that are meaningfulto an elongate instrument) and/or alignment algorithms. Registration mayalso involve other steps such as locating the tip or other points ofinterest of the fiber and their orientation with relation to theinstrument. These pieces of information (for instance the orientationand location of the tip), can be used for such applications such asinstinctive driving described in detail in applications previouslyincorporated by reference. In certain variations, a coordinate system ofa shape sensing fiber may be registered with an elongate instrument,catheter, splayer or other associated structures through the use ofmechanical structure and/or algorithms. In certain variations,registration may allow a shape sensing fiber to be used in an instrumentsuch as a catheter for localization, e.g., particular, instinctive,driving, shape feedback, and positional driving.

Methods and apparatus for registration or calibration of a fibercoordinate system to a robotic catheter assembly coordinate system willbe described herein. It should be understood that similar methods andapparatus may be used for registration of a fiber with any system, forexample any flexible elongate member including but not limited to manualcatheters, endoscopes, bronchoscopes, or guide wires as well as anysystem with rigid linkages.

FIGS. 11 and 12 illustrate an example of a catheter assembly 150 with anintegrated fiber 152. As previously described in detail, the fiber canbe fixed to the distal tip of the catheter 151, run down the length of alumen within the catheter, and be integrated or positioned intocomponents of the splayer 153 or a structure associated with thesplayer. The fiber 152 can be fixed in six degrees of freedom, less than6 degrees of freedom or no degrees of freedom at its proximal end ororigin to the splayer 153 or a structure fixed to the splayer, e.g., aregistration fixture 156.

In order to register a fiber coordinate system to a catheter coordinatesystem, it may be desirable to use a full fiber length registrationmethod including placing the entire or substantially the entire catheterassembly including the splayer and catheter with integrated fiber inknown positions and orientations in a full fiber length registrationfixture (e.g., a slide or plate or other structure) and then collectingdata from fiber sensors within the fiber. The data collected from thisprocess is used to calculate a transform or transformation matrixbetween the fiber coordinates and the catheter or splayer coordinates,which are physically tied to the registration fixture. The origin of thefiber coordinate system may be on the partial fiber length registrationfixture (which may be affixed to the splayer) and the location of thepartial fiber length registration fixture is determined through thisregistration process.

Also, the location of the fiber within the catheter may be determined.The orientation in roll and/or insert of the fiber distal tip glued oraffixed within the catheter distal tip may be determined. The fiberincludes a local coordinate system and the fiber can provide thelocation of the fiber tip. Registration provides the location of thecatheter relative to the fiber.

Registration using the full fiber length registration method, which mayuse the entire or substantially the entire length of the fiber, can beused in one variation where an origin or proximal section of a fiber mayor may not be fixed to the splayer or a partial fiber lengthregistration fixture. The transformation of or the transformation matrixfrom the fiber coordinate system to the physical coordinate system ofthe splayer or catheter can be determined by placing the catheter withintegrated fiber and splayer in a well machined and toleranced fullfiber length registration fixture having known mechanical structures(such as curves, points, or grooves).

FIG. 13 shows a variation of a full fiber length registration fixture160 for registering a shape sensing fiber 162 to a catheter 162. Inparticular, FIG. 13 shows a full fiber length registration fixture 160for registering or calibrating shape using the entire or substantiallythe entire fiber 162 length. The full fiber length registration fixture160 may have a splayer holder 163 as well as several grooves 164including two grooves each with a 180 degree u-turn shape and a straightline groove. The splayer holder 165, grooves 164 and the full fiberlength registration fixture 160 may be manufactured or cut out of glassor another similar material as a single unit resulting in tighttolerances as small as +/−0.001″ for example resulting in minimalangular error and accurate known location of the grooves 164 relative tothe splayer holder 163. The splayer holder 163 is configured to serve asa receptacle for receiving or attaching to the base of a splayer 165while the grooves 164 provide for several various shapes in which theentire or substantially the entire shape of the catheter 161 with fiber162 may be fit. Where there is a systematic shape sensing error,averaging the registration from the different shapes to determine afinal registration may result in a more accurate transformation matrix.

Various shapes for performing full fiber length registration on the fullfiber length registration fixture may be utilized, e.g., shapes thatextend in the forward, left, right, up, and/or down directions. Thelonger the lever arm or length of the fiber for calibration, the smallerthe angular error should be. The accuracy of the registration proceduremay depend on the accuracy of measurements that may be obtained and/orthe fixture type or design.

In an alternative variation, the full fiber length registration fixturecan include a splayer holder and instead of grooves can include variouspoints placed in known locations relative to the splayer holder. Withthis full fiber length registration fixture, the tip of the catheter maybe touched to the known points to calculate a transformation matrixbetween the fiber coordinate system and a physical coordinate system ofthe splayer or elongate instrument.

As described full fiber length registration involves registration and/orcalibration on the entire or substantially entire length of a shapesensing fiber. When using full fiber length registration, assuming theshape sensing has close to zero error, having a long lever arm may allowfor a more accurate calculation of the coordinate system transformationand provide a more accurate registration. Full fiber length registrationmay not require the use of fiducials in the mechanical registrationfixture or structure if the fiber origin or a section at the fiberproximal end is fixed with the tolerance needed to maintain alignmentout of the factory and is not able to rotate or change position once itis registered or calibrated.

However, in certain applications, the fiber origin may not be fixed withthe tolerance needed to maintain alignment out of the factory. Also, thenatural twist or roll during full fiber registration of the catheter inwhich the fiber is integrated may also provide a source of error duringregistration. If the elongate instrument twists while positioned in thegrooves in the registration plate, the determined location of the fibermay no longer be accurate as the error lies within the diameter of theelongate instrument. In certain variations, an elongate instrument maynot twist and/or the elongate instrument may have a diameter of about 2mm (such as a vascular catheter) where 2 mm may be on the order of ashape sensing error such that any error due to twist is negligible. Thusadditional registration or calibration beyond full fiber lengthregistration may be necessary.

An alternative or additional registration or calibration method includespartial fiber length registration, e.g., at the proximal end of thefiber, or at least a partial length of the fiber registration. Partialfiber length registration can involve registration on any partial lengthor section of a shape sensing fiber. In certain variations, at least asection or portion of a fiber may be fixed or grounded relative to anelongate instrument or to a structure associated with an elongateinstrument, such as a partial fiber length registration fixture (e.g., aplate or slide) or the splayer, such that the fiber may be registered tothe elongate instrument or to a structure associated with the elongateinstrument and the fiber may provide shape sensing or measuring of theelongate instrument. Partial fiber length registration may be performedin an ongoing manner, e.g., during use of an elongate instrument.Optionally, partial fiber length registration may be performed where noportion of the fiber is fixed to an elongate instrument or associatedstructure.

Referring back to FIGS. 11-12 a variation of a partial fiber lengthregistration fixture 156 providing for partial fiber length registrationto register a shape sensing fiber to a catheter is shown. Theregistration fixture 156 is in the form of a vertical plate (e.g., asharkfin) that is mountable on a center axis of the splayer 153. Agroove 157 or track may be cut into the plate. The groove 157 mayreceive the shape sensing fiber 152, such that at least a portion of thefiber 152 sits inside the groove 157. A fiber 152 may include a serviceloop 158 which allows the length of the fiber 152 within an elongateinstrument to increase or decrease with the bending of the catheter 151.The service loop 158 may be positioned within the groove 157 and aproximal section or origin of the fiber 152 may be fixed to fixture 156.The service loop 158 can help maintain accuracy of shape sensing throughthe fiber. In one variation, the service loop 158 may maintain less thanabout a 15 mm radius of curvature. The fiber may optionally have about a2 cm straight section at its proximal end to allow shape algorithms toinitialize.

FIG. 14A-14B show two alternative variations of partial fiber lengthregistration fixture 166 structures including a known 2D shape having a90 degree circle plus a straight section. The tolerance of the grooves157 or tracks in the fixture 166 may be about 250 microns because anangular error of about 0.05 degrees may lead to a 1 mm error on a 1 mstraight length. Tolerances may be relaxed if angles are corrected for aknown plane and/or a known heading.

In the partial fiber length registration fixture 176 shown in FIG. 14B,various points along the service loop 178 of the fiber 172 may be usedto find two Euler angles to align the fiber 172 to a particular plane.This would reduce the tolerances to having a level plane (within about200 microns) and provide a shallow track or groove 177 that holds thefiber 172. A straight section along the fiber 172 may be used to correctheading. The straight section may have a pitch tolerance of about 200microns to reduce mechanical alignment error.

In certain variations, successive information further down the fibershape, e.g., distally, may be used to correct for heading error, e.g.,in situations where the reference or structure is readjusted to be theshaft of a catheter. This type of an adjustment would allow a comparisonof the fiber shape to a catheter model. Optionally, the straight sectionof the hypotube near the proximal end of a catheter may be used tocorrect the heading from a splayer, e.g., where there is excessive errorfrom the service loop or if the catheter becomes non-orthogonal to thesplayer. Readjustments for the origin of the catheter shaft, based uponknown fiber lengths in the splayer, may be made.

Registration structures or fixtures may take on additional alternativeconfigurations. In one variation, a mechanical structure may beincorporated into a vertical handle or other functional, ergonomicstructure on top of or adjacent a splayer. In certain variations, afiber service loop may travel in plane or out of plane. Registrationstructures or fixtures may be positioned parallel to a splayer, bringinga fiber out of plane. For example, a plate may be positioned above orbelow a splayer and pulleys. Where a registration plate is located belowthe pulleys, the fiber may extend easily in plane with the service loop,e.g., where the fiber is placed in the lower lumen of a catheter. Anexample of an out of plane, horizontal mechanical registration structureor fixture is shown in FIG. 9A. As described supra, a service loop mayhave a variety of shapes or configurations. A service loop may spiral ina left hand or right hand direction and/or have a configuration similarto a bird's eye or jog shape as shown in FIGS. 10A-10C.

In some variations, in order to register the coordinate system of thefiber with the coordinate system of the catheter, full fiber lengthregistration and/or the partial fiber length registration can beperformed using the registration fixtures described in detail above. Themethod of registration, i.e., whether to use full fiber lengthregistration, partial fiber length registration or both, depends on themechanical stability of the 6 degrees of freedom at the origin of thefiber. In one variation, where all six degrees of freedom of the fiberorigin can be securely fixed with regard to a section of the catheter orassociated structure, a full length fiber registration can be performedas described above, e.g., during manufacturing, providing all sixdegrees of orientation of the catheter. In another variation, where thefiber origin can be partially fixed with less than six degrees offreedom, then both full fiber length and partial fiber lengthregistration can be performed. In another variation, where the fiberorigin is floating where no degrees of freedom are fixed, full fiberlength registration and/or partial fiber length registration and/or aregistration technique, such as known shape registration, can beperformed.

Six degrees of freedom of a fiber can be fixed in certain variationswhere a section of the fiber, e.g., a section located at the proximalend or beginning of the fiber, is fixed or anchored relative to theelongate instrument or to a structure associated with the elongateinstrument. Once a fiber is fixed relative to an elongate instrument orto a structure associated with the elongate instrument, the fiber maymeasure where that fixed point is relative to every other point on thefiber. In order to convert that relative position into an absoluteposition (e.g., the position of the tip of an elongate instrument) thelocation of that fixed point may be determined relative to some knownreference (e.g., an elongate instrument, splayer, robot, or patient). Inone variation, a point on the fiber may be fixed or glued down tosomething static, such that the fixed point of the fiber does not move.The location of the fixed point is then determined. All six degrees offreedom at the fixed point of the fiber are known, and every other pointon the fiber may be measured relative to that fixed point. An anchoredor fixed section of a fiber provides a stable starting position andorigin for measuring the shape of the fiber, such that a relativemeasurement of the fiber shape (a measurement of one point on a fiberrelative to another point on the fiber) may be converted into anabsolute measurement of the elongate instrument shape.

In certain variations, a section of the fiber may be attached or affixedto an anchoring mechanism, where the anchoring mechanism may be glued orotherwise affixed or coupled to or positioned on an elongate instrumentor a structure associated with the elongate instrument to fix, position,or anchor the fiber in place. Examples of anchoring mechanisms includebut are not limited to a hypotube, tube or block made from silica,quartz, glass or other similar material. The anchoring mechanism mayhelp maintain a section of the fiber in a straight configuration,providing a launch region on the fiber which may allow the start orbeginning of the fiber to be located. In certain variations, the launchsection of a fiber may be in a straight configuration to initialize aparticular algorithm. In other variations, a launch section of a fibermay not be straight but may have one or more curves. The anchoringmechanism may be used to fix or anchor a section of the fiber or theorigin of the fiber, preventing the fixed section or origin from movingin any of the six degrees of freedom such that an accurate registrationof the fiber may be performed.

In certain variations, a system for measuring a shape of an elongateinstrument includes a fiber and an anchoring mechanism where the fibermay be affixed to the anchoring mechanism and the anchoring mechanismmay be affixed to the elongate instrument or to a structure associatedwith the elongate instrument. The anchoring mechanism may be in the formof a block, plate or slide. The anchoring mechanism may be made fromsilica, glass, quartz or a similar material and include a groove ortrack in which the fiber may be affixed or glued to bond the fiber tothe anchoring mechanism. For example, the block may include a groove ortrack and the fiber may be affixed to the block within the groove ortrack. Optionally, the fiber may be affixed or glued to a surface of theblock, e.g., where the block does not have a groove. The anchoringmechanism may be made from a material having a similar or identicalthermal coefficient to that of the fiber.

In another case, it may be difficult to mechanically fix all six degreesof freedom of the fiber. For instance, the position of the fiber couldbe fixed well, as can the yaw and pitch by using a thin slot, but sincethe fiber is so thin, it could roll freely in the track. In a case suchas this, less than 6 degrees of freedom can be determined from the fiberorigin and from full fiber length registration. Thus, the remainingdegrees of freedom can be determined using partial fiber lengthregistration fixtures prior to and possibly during the procedure orduring use of the catheter or elongate instrument if the fiber positionchanges in any degree of freedom. For instance, these other degrees offreedom can be determined by a heading, plane, or known shape in theservice loop or splayer as previously described. This scheme can also beused if an error through the service loop or a section of the earlyshape measurement induces an error in one or more of the degrees offreedom of the origin; a secondary plane, shape, or heading can be usedto correct these unknowns or errors in real time.

In alternative variations, the fiber origin may not be mechanicallysecured so no degrees of freedom can be fixed or determined from theorigin of the fiber. In such a case, full fiber length registration,partial fiber length registration and/or one or more features or shapescan be used to determine one or more degrees of freedom. For instance, aplane from the service loop and a heading from the hypotube in thecatheter may be used to determine all six degrees of freedom. In anothervariation, a well machined shape track (tolerance track shape trackpositioned in the device in a well-toleranced way) may be used todetermine all six degrees of freedom of the system.

The above processes for registering a fiber may be used together or inthe alternative to determine or measure one or more of the six degreesof freedom of a catheter or other elongate instrument. However, incertain variations, it may be difficult to obtain accurate or precisemeasurements in certain sections of a fiber, e.g., in the service loop.Thus, while one or more degrees of freedom may be measured based on apoint on the fiber that is fixed or glued down, a known shape on thefiber may also be located to provide the remaining degrees of freedom.The known shape may be used to measure or detect one or more degrees offreedom to help correct for one or more errors that may have accumulatedwhen measuring sections of the fiber, such as a service loop, that havetight bends or that may be difficult to measure. The tighter the bendsimposed on a fiber are, the more difficult it may be for the fiber tomaintain accuracy of its shape measurement. Use of the known shaperegistration technique in combination with the fixed fiber registrationinformation may improve overall shape measuring accuracy.

In certain variations, a process for registering a fiber may or may notrequire fixing a point on the fiber. A known shape may be imposed orplaced on the fiber and the shape may be recognized in a measurementcoming from the fiber. The imposed shape is located in the measurementfrom the fiber and then lined up or registered with the known mechanicalshape, machined to precise tolerances, providing an on the flyregistration. The location of the shape in space and/or the orientationof the shape may be known or determined. For example, the shape may bereferenced to certain data on a splayer. In certain variations, theshape may be located on a fixture, e.g., plate or slide, where the shapeis toleranced tightly and the location of the shape is known relative toanother point on the fixture, plate or slide.

The known shape registration technique may be used in combination withfixed fiber registration information obtained according to the fixedfiber registration techniques described above. In other variations, theknown shape registration techniques may be used alone to ascertain oneor more degrees of freedom or all six degrees of freedom of an elongateinstrument by registering a fiber to an elongate instrument.

In another variation, twist or slide of the fiber may be difficult todetect or measure using the fixed fiber technique, so twist or slide maybe detected or measured at a different point on the fiber, e.g., on adifferent plane, using the known shape technique.

In certain variations, the known shape may be placed anywhere in anelongate instrument, catheter or splayer, e.g., a known 2D or 3D shape.The physical structure for maintaining a shape may be located in aposition that maintains the fiber shape and allows the shape to berecognized. The shape may be in a position where it is mechanicallyfixed relative to some other known structure or reference that has aknown location. The shape may be structurally integrated into anelongate instrument, catheter, splayer, or fixture referenced to asplayer or robot, an introduction site (e.g., a known jog shape at astabilizer at an introduction site) or into another component orstructure associated with an elongate instrument. The above structuresand sites may be used as references. Optionally, the shape may bereliably referenced to a known spot, origin or structure, such assomething affixed or glued to a patient or to a physical organ.

The properties or configurations of known shapes used in the known shaperegistration technique may depend on the particular degrees of freedomto be obtained. For example, a bird's eye, jog, spiral and/or straightline shape in a fiber may be utilized. In certain variations, one ormore known shapes (different or similar) may be placed along differentlengths or sections of a fiber. The shapes may be used or read tomeasure or detect one or more degrees of freedom to calibrate out anyerrors that may have accumulated from measurements taken using the fixedfiber registration technique.

In certain variations, known shapes may be placed in an elongateinstrument or other structure associated with the elongate instrument,e.g., by being mechanically placed therein. A lumen of an elongateinstrument may be provided with a jog shape or other suitable shape. Incertain variations, a straight hypotube holding a proximal section of afiber may provide a known shape. The hypotube shape is straight andrecognizable and its location is also known. The stiffness of thehypotube may be altered to make it stiffer and more accurate. A straightline shape may be placed in various sections of an elongate instrumentor fiber and utilized as a known shape. A known shape may be straight,curved or any other possible configuration. A known recognition shapemay be placed anywhere along the length of a fiber, elongate instrument,catheter, plate, splayer or other structure. Any known shape may allowfor the measurement or ascertaining of one or more degrees of freedom.

Information about the shapes in a fiber in a fixture, splayer, or otherstructure located anywhere along the fiber may be used for performingregistration or alignment. In certain variations, the shapes may be usedfor performing registration or alignment depending on the tolerances ofthe manufacturing process. In certain variations, the shapes may be usedto confirm or reacquire registration or alignment information or toreacquire or check one or more degrees of freedom.

In certain variations, various registration techniques are provided thatallow for all six degrees of freedom of a coordinate frame to be solvedor ascertained with respect to another coordinate frame. In onevariation, a fiber origin may be glued or otherwise affixed to anelongate instrument or structure associated with an elongate instrumentand full fiber length registration or calibration may be utilized toascertain all six degrees of freedom of an elongate instrument byregistering the coordinate system of the fiber to the coordinate systemof the elongate instrument.

Any of the various devices, systems or methods described herein forintegrating or registering a fiber in or to an elongate instrument orother structure may apply to, be performed on or be incorporated in anymanually and/or robotically controlled or steerable elongate instrumentsor catheters. FIG. 18 shows on example of a manually operated elongateinstrument or catheter assembly 300 having a base 301 or handle, acontrol knob 306, a catheter 302, an integrated fiber 303, and a serviceloop 304 held in a registration fixture 305, which may be coupled to thebase 301, the catheter 302 or handle or any other structure fixed orcoupled to the catheter.

FIG. 19 shows a flow chart showing one example of a method forregistering a fiber to an elongate instrument or other structure.Registration may result in producing a transformation matrix.Translations or rotations in any of the degrees of freedom may alsoconstitute registration. The registration process involves matching twosubsets of points or orientations between a “known” data set (e.g., froma fixture, images, etc.) and a “measured” data set (e.g., a data setobtained from the fiber or sensor of interest). The registration may befound iteratively. A guess of the registration can be made and appliedto the measured data. This transformed data is then compared to theknown data, for instance through RMS positional error or any otherdesired metric. If this metric is determined to show that the known andtransformed measured data have low error, then the cycle ends, and theregistration has been found. If the metric shows that the known andtransformed measured data do not adequately line up with each other,then the metric is used to produce another guess and the cycle may berepeated over again.

FIG. 20 is the same as FIG. 25A of U.S. patent application Ser. No.12/837,440, now U.S. Pat. No. 8,780,339, which was previouslyincorporated by reference. Referring to FIG. 20, a position determiningsystem 730 is depicted operatively coupled to each of the fibers 716.The position determining system 730, generally comprising an opticalradiation emitter and detector, and a computing system to analyzedetected optical radiation, may be operatively coupled to each of thefibers 716 via the cart 726. The position determining system 730 isconfigured to analyze data from the fibers 716 as the arms 728 aremaneuvered and determine changes in elongation of the fibers 716. Somesystems, such as those available from Luna Innovations, Inc., may beconfigured to utilize sensed deflection data to determine the spatialpositioning or shape of a particular fiber or bundle of fibers. Althoughit is referred to herein as a “position determining system,” such systemmay also analyze, calculate and/or determine other information using thedata from the fibers, including without limitation, stress, strain orelongation, forces, and/or temperature. The positioning determiningsystem 730 is also operatively coupled to the operator control station722 or control system of the instrument system, such that positioninformation as determined by the position determining system 730 may berelayed to the operator control system 722 to assist in navigation andcontrol of the instrument system. In this illustration, the surgicalworkstation 724 carries three robotically controlled arms 728, and themovement of the arms 728 is remotely controllable from the controlstation 722. In other variations, the cart 726 may carry a varyingnumber of arms 728 (i.e., one or more arms; or two or four arms)depending on the particular configuration.

In certain variations, a housing, e.g., a splayer or instrument driver,may be coupled to a proximal portion of any of the elongate instrumentsor devices described herein. The housing may include an interface forreceiving an actuating force and transferring the actuating force to theelongate instrument to articulate a distal portion of an elongateinstrument. A shape sensing fiber may be integrated in the elongateinstrument and may include a first portion positioned within the lumenof the elongate instrument. Optionally, the fiber may also include asecond portion positioned within the housing, where the second portioncan include a service loop which allows for sliding of the fiber withinthe lumen of the elongate instrument when the distal portion of theelongate instrument is articulated.

In any of the variations described herein, the particular shape that maybe utilized in a fiber for registration purposes may depend on the avariety of factors, such as, the amount of error accrued going throughthat shape, how much slack is needed in a service loop, and any spatialrestriction imposed by the particular system in which the fiber is beingutilized. For example, in a robotic catheter system, space may berestricted due to the positioning of a guide wire manipulator or othercomponent of the system. Examples of fiber shapes have been describedsupra, and include but are not limited to a bird's eye, jog or spiralshape or any other shape.

In certain variations, whether using a full or partial lengthregistration fixture or any other known shape, the shape may includecurves with large bends and a minimum number of turns to help minimizeerror. A shape may also be configured in a manner that allows the datato have long lever arms, e.g., a shape may cover the largest volumepossible as permitted by the space available, to achieve an optimalregistration. A shape may be configured in a manner, e.g., that balancesa desired shape that minimizes error while occupying an adequate amountof space on a registration fixture (e.g., a shark fin or plate). In onevariation, a shape may include a u-turn having a large bend radius.

As described supra, in certain variations a region of the fiber, e.g.,the proximal region or origin of a fiber may be configured to facilitateregistration of a fiber to an elongate instrument. In one variation, aportion of a fiber may be fixed in one to six degrees of freedom byfixing or gluing the fiber to a block, where the block is in a fixedlocation relative to an elongate instrument or splayer.

In another variation, a fiber may positioned or configured into a knownshape, plane, line, vector, orientation or other position within aregistration fixture that is attached to or fixed in a known locationrelative to an elongate instrument, splayer or other structure. One tosix degrees of freedom of the fiber may be deduced based on the knownshape or other orientation. Optionally, an unknown arbitrary shape maybe utilized from which zero degrees of freedom of the fiber may bededuced.

Once the proximal or other region of the fiber is configured in anymanner described herein, one or more or a combination of registrationtechniques may be utilized to obtain one to six degrees of freedom ofthe fiber relative to the elongate instrument, a splayer, a housing, acatheter, a registration fixture or other structure of interest. One tosix degrees of freedom of the fiber may be measured or ascertainedrelative to an elongate instrument, e.g., via a structure or fixturewhose location relative to an elongate instrument is known. In onevariation, a fiber may be fixed in six degrees of freedom such that allsix degrees of freedom of the fiber can be deduced in a fixture whichmay hold the entire or substantially the entire length of the fiber. Thefixture may or may not be attached to the elongate instrument. Theresulting registration or calibration may not change where the fiber isfixed or glued in place. If less than six degrees of freedom of thefiber are obtained, the remaining degrees of freedom may be deduceddynamically to register the fiber to the elongate instrumentdynamically, during use of the elongate instrument.

In another variation, where the fiber is in a known shape or isconfigured in a known plane or other orientation in a fixture, (e.g., afixture attached to the elongate instrument), one to six degrees offreedom may be deduced during use of the elongate instrument. A fiberpositioned in a known 2D shape may be utilized to determine one to sixdegrees of freedom. A fiber configured in a known plane may be utilizedto determine at least one degree of freedom.

In other variations, other features may be utilized to register a fiberto an elongate instrument or other structure during use of thatinstrument or other device or structure. For example, various shapes inan anatomy coupled with a CT image or 3D model; a known shape in anintroducer through which the elongate instrument passes; the knownlocation of a leader and a sheath splayer; and/or other features may beutilized to register a fiber to a desired instrument or other structure.

In any of the variations described herein, the shape of the fiber orelongate instrument may be obtained by collecting data along the fiberfrom the proximal end to the distal end of the fiber. In certainvariations, registration data (e.g., full length or partial length) maybe stored on the splayer EEPROM, on a USB, a server, or other portablememory device, from which the data may be accessed.

In another variation, a fiber may be placed or configured in a knownshape in various locations for obtaining registration data. For example,the fiber may be placed in a known shape between the registrationfixture and the Lune box or controller. In another example, a knownshape may be placed between the service loop or registration fixture andthe distal end of the fiber, e.g., at the introducer site. In anotherexample, a known shape may be placed on a table or patient bed which mayallow the fiber to be registered to the bed to minimize or avoidmovement from an RCM or setup joint.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. The system may also include a shape sensing fiber, where atleast a first portion of the fiber is positioned in the lumen of theelongate instrument. A second portion of the fiber may be fixed orotherwise attached in a known location or position relative to theelongate instrument or to another structure such that the coordinatesystem of the fiber can be matched to the coordinate system of theelongate instrument to register the fiber to the elongate instrument. Incertain variations, registration may allow the shape of an elongateinstrument to be detected or determined, e.g., based on the shape of thefiber.

The second portion of the fiber may be fixed such that one or moredegrees of freedom of the fixed portion the fiber may be measured orascertained relative to the elongate instrument or other structure.Optionally, the second portion of the fiber may have a known shape.

In certain variations, the system may include a registration fixture.The second portion of the fiber may be fixed in a known location on theregistration fixture and the registration fixture may be in a knownlocation relative to the elongate instrument. The registration fixturemay have grooves or slots for holding at least a portion of the fiberand/or at least a portion of the elongate instrument in a known shape,orientation or position.

In certain variations, the second portion of the fiber may be configuredin a known position or orientation in a registration fixture such thatdata can be collected regarding the position or orientation of at leasta partial length of the second portion of the fiber. The collected datamay be used to calculate a transform between the coordinate system ofthe fiber and the coordinate system of the elongate instrument or otherstructure, to perform registration.

In certain variations, a housing may be coupled to a proximal portion ofthe elongate instrument. The housing may include an interface forreceiving an actuating force and transferring the actuating force to theelongate instrument to articulate a distal portion of the elongatedinstrument. The registration fixture may be positioned on or in thehousing. A portion of the fiber may be positioned within the housing,where the portion of fiber includes a service loop. The service loop mayallow for sliding or displacing of the fiber within the lumen of theelongate instrument when the distal portion of the elongate instrumentis articulated.

In certain variations, the system may be removably coupled to aninstrument driver and a controller which controls actuation of theelongate instrument. Actuation motion may be transferred from thecontroller to the system via the instrument driver to articulate thedistal end of the elongate instrument in at least one degree of freedom.Any variation of the system or assemblies described herein may bedisposable.

In certain variations, a method for registering a fiber to an elongateinstrument and/or detecting the shape of an elongate instrument mayinclude one or more of the following steps. An assembly having anelongate instrument and a shape sensing fiber may be operated. Theelongate instrument may have a proximal end, a distal end and at leastone lumen defined therein, where least a first portion of the fiber maybe positioned in the lumen of the elongate instrument. At least a secondportion of the fiber may be fixed in a known location or positionrelative to the elongate instrument or to another structure. A positionof the fixed portion of the fiber may be measured or ascertainedrelative to the elongate instrument to match the coordinate system ofthe fiber with the coordinate system of the elongate instrument toregister the fiber to the elongate instrument.

In certain variations, one or more degrees of freedom of the fixedportion the fiber may be measured or ascertained relative to theelongate instrument. Optionally, one or more degrees of freedom of aportion of the fiber configured in a known shape, plane or otherorientation may be measured or ascertained relative to the elongateinstrument. Measuring or ascertaining or matching of the coordinatesystems may be performed while the elongate instrument is positionedwithin an anatomical region. The registration may allow the shape of theelongate instrument to be detected.

In certain variations, saved registration data regarding registrationbetween the coordinate system of the fiber and the coordinate system ofthe elongate instrument may be accessed from a memory component todetermine the shape of the elongate instrument.

In certain variations, the assembly may be removably coupled to aninstrument driver and a controller which controls actuation of theelongate instrument, wherein actuation motion is transferred from thecontroller to the elongate instrument via the instrument driver toarticulate the distal end of the elongate instrument in at least onedegree of freedom.

In certain variations, the assembly may include a registration fixture.The second portion of the fiber may be fixed in a known location on theregistration fixture and the registration fixture may be in a knownlocation relative to the elongate instrument. One or more degrees offreedom of the second portion of the fiber may be measured orascertained relative to the registration fixture and the elongateinstrument. A registration fixture may have grooves for holding at leasta portion of the fiber in a known shape, orientation or position.

In certain variations, data may be collected regarding the position ororientation of at least a partial length of the fixed portion of thefiber configured in a known position or orientation in a registrationfixture. The collected data may be used to calculate a transform betweenthe coordinate system of the fiber and the coordinate system of theelongate instrument or other structure.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. The system may also include a shape sensing fiber, wherein atleast a first portion of the fiber is positioned in the lumen of theelongate instrument. A second portion of the fiber may be configured ina known shape, plane or other orientation relative to the elongateinstrument or to another structure such that the coordinate system ofthe fiber may be matched to the coordinate system of the elongateinstrument to register the fiber to the elongate instrument.

In certain variations, one or more degrees of freedom of the secondportion of the fiber may be measured or ascertained relative to theelongate instrument. In certain variations, the second portion of thefiber may be positioned between a distal end of the fiber and a serviceloop located at a proximal end of the fiber. The second portion of thefiber may be held within a registration fixture associated with theelongate instrument. In one variation, the second portion of the fibermay have a u-turn configuration with a large bend radius to minimizemeasurement error and fit within a registration fixture associated withthe elongate instrument. In certain variations, the second portion ofthe fiber may be configured in a known position or orientation in aregistration fixture such that data can be collected regarding theposition or orientation of at least a partial length of the secondportion of the fiber. The collected data may be used to calculate atransform between the coordinate system of the fiber and the coordinatesystem of the elongate instrument or other structure.

In certain variations, a method of detecting the shape of an elongateinstrument may include one or more of the following steps. Operating anassembly having an elongate instrument and a shape sensing fiber, wherethe elongate instrument may have a proximal end, a distal end and atleast one lumen defined therein may be performed. At least a firstportion of the fiber may be positioned in the lumen of the elongateinstrument and at least a second portion of the fiber may be configuredin a known shape, plane or other orientation. A position of the secondportion of the fiber may be measured or ascertained relative to theelongate instrument to match the coordinate system of the fiber with thecoordinate system of the elongate instrument to register the fiber tothe elongate instrument.

In certain variations, one or more degrees of freedom of the secondportion of the fiber may be measured or ascertained relative to theelongate instrument. In certain variations, the second portion of thefiber may be positioned between a distal end of the fiber and a serviceloop located at a proximal end of the fiber. In other variations, asecond portion of the fiber may be positioned on a portion of the fiberfixed to an operating table or bed.

In other variations, a second portion of the fiber may be held within aregistration fixture associated with the elongate instrument.Optionally, data may be collected regarding the position or orientationof the second portion of the fiber configured in a known shape, plane orother orientation in a registration fixture. The collected data may beused to calculate a transform between the coordinate system of the fiberand the coordinate system of the elongate instrument or other structure.

In certain variations, a method for detecting the shape of an elongateinstrument may include one or more of the following steps. Operating anassembly having an elongate instrument and a shape sensing fiber may beperformed. The elongate instrument may have a. proximal end, a distalend and at least one lumen defined therein. At least a first portion ofthe fiber may be positioned in the lumen of the elongate instrument andat least a second portion of the fiber may be fixed in a known locationrelative to the elongate instrument or to another structure. Savedregistration data may be accessed regarding registration between thecoordinate system of the fiber and the coordinate system of the elongateinstrument from a memory component to determine the shape of theelongate instrument. Optionally, the structure may be a registrationfixture which may be positioned in a known location relative to theelongate instrument.

In certain variations, one or more degrees of freedom of the fixedportion the fiber may be measured or ascertained relative to theelongate instrument. This step may be performed while the elongateinstrument is positioned within an anatomical region. In certainvariations, one or more degrees of freedom of a portion of the fiberconfigured in a known shape, plane or other orientation may be measuredor ascertained relative to the elongate instrument.

In certain variations, an assembly may be removably coupled to aninstrument driver and a controller which controls actuation of theelongate instrument, wherein actuation motion is transferred from acontroller to the elongate instrument via the instrument driver toarticulate the distal end of the elongate instrument in at least onedegree of freedom.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and one or more lumens definedtherein. The system may include a shape sensing fiber, where at least aportion of the fiber may be positioned within the lumen of the elongateinstrument. The shape sensing fiber may have a service loop which allowsfor sliding or displacing of the fiber within the lumen of the elongateinstrument when a distal portion of the elongate instrument isarticulated. The system may also include a coil positioned within thelumen, and surrounding or at least partially or substantiallysurrounding the fiber. The coil may be slideable within the lumen andthe coil may maintain the lumen in an open state during articulation ofthe elongate instrument.

In certain variations, the coil may be positioned in a distal section offirst lumen. In certain variations, a fiber may be free floating withinthe coil.

In certain variations, a proximal section of the first lumen may beincorporated into a braid in the elongate instrument. The braid mayoptionally be configured to wind around the proximal section of thelumen as well as a working lumen and control wire lumen of the elongateinstrument, in a diamond braid pattern.

In certain variations, the elongate instrument may have a tip which isreinforced to support or protect at least a portion of a fibertermination positioned therein. The elongate instrument tip may includea control ring and the fiber may extend through or along the controlring.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. The system may include a housing coupled to a proximal portionof the elongate instrument, where the housing includes an interface forreceiving an actuating force and transferring the actuating force to theelongate instrument to articulate a distal portion of the elongatedinstrument. The system may also include a shape sensing fiber. At leasta first portion of the fiber may be positioned within the lumen of theelongate instrument, and a second portion of the fiber may be positionedwithin the housing. The second portion of the fiber may include aservice loop which allows for sliding or displacing of the fiber withinthe lumen of the elongate instrument when the distal portion of theelongate instrument is articulated.

In certain variations, the interface may be configured to couple to anactuator. The actuating force may be delivered via robotic control in arobotically controlled or steerable elongate instrument system. Incertain variations, the interface may include a knob for a user tomanually deliver such actuation force.

In certain variations, at least a portion of the sensing fiber may befixed relative to the elongate instrument or to a structure associatedwith the elongate instrument. At least a portion of the fiber positionedwithin the lumen of the elongate instrument may be decoupled or freefloating relative to the lumen of the elongate instrument.

In certain variations, the housing may include a registration fixture.At least a portion of the service loop may be held within a groove ortrack of the registration fixture. The service loop may be configured toslide in a single plane within the registration fixture. The serviceloop may have a shape configured to fit substantially within theregistration fixture.

In certain variations, the registration fixture may include a pocketpositioned thereon. The fiber may include an anchoring mechanism affixedto a proximal portion of the fiber, wherein the anchoring mechanism maybe configured to slide within the pocket in no more than one degree offreedom or in one or more degrees of freedom. The fiber may include ananchoring mechanism affixed to a proximal portion of the fiber, whereinthe anchoring mechanism may be affixed within the pocket to fix a knownfiber length. Optionally, the anchoring mechanism may include a silicablock or straight tube.

In certain variations, a method of actuating an elongate instrument mayinclude one or more of the following steps. A system may be operativelycoupled a to a controller. The system may include an elongateinstrument; a housing coupled to a proximal portion of the elongateinstrument, where the housing comprises an interface for receiving anactuating force and transferring the actuating force to the elongateinstrument to articulate a distal portion of the elongate instrument;and a shape sensing fiber. The elongate instrument may have a proximalend, a distal end and at least one lumen defined therein. At least afirst portion of the fiber may be positioned within the lumen of theelongate instrument, and a second portion of the fiber may be positionedwithin the housing. The second portion of the fiber may include aservice loop. Actuating motion may be transferred from the controller tothe system to articulate the distal portion of the elongate instrumentin at least one degree of freedom, where the service loop allows thefiber to slide or be displaced within the lumen of the elongateinstrument when the distal portion of the elongate instrument isarticulated, thereby controlling the amount of strain the fiber issubjected to and maintaining shape sensing properties of the fiber.

In certain variations, the housing may include a registration fixture.At least a portion of the service loop may be held within a groove ortrack of the registration fixture. The service loop may be configured toslide in a single plane within the registration fixture. The serviceloop may have a shape configured to fit substantially within theregistration fixture. In certain variations, at least a portion of thefiber positioned within the lumen of the elongate instrument may bedecoupled or free floating relative to the lumen of the elongateinstrument.

In certain variations, a system may include an elongate instrumenthaving a proximal end, a distal end and at least one lumen definedtherein. A housing may be coupled to a proximal portion of the elongateinstrument, wherein the housing includes an interface for receiving anactuating force and transferring the actuating force to the elongateinstrument to articulate a distal portion of the elongate instrument.The system also includes a shape sensing fiber. At least a first portionof the fiber may be positioned in the lumen of the elongate instrument.At least a second portion of the fiber may be positioned in the housingsuch that the coordinate system of the fiber can be matched to thecoordinate system of the elongate instrument to register the fiber tothe elongate instrument. The second portion of the fiber may include aservice loop which allows for sliding or displacing of the fiber withinthe lumen of the elongate instrument when the distal portion of theelongate instrument is articulated.

In certain variations, at least a portion of the second portion of thefiber may be fixed such that one or more degrees of freedom of the fixedportion the fiber may be measured or ascertained relative to theelongate instrument. In certain variations, at least a portion of thesecond portion of the fiber may be configured in a known shape, plane orother orientation such that one or more degrees of freedom of theportion of the fiber may be measured or ascertained relative to theelongate instrument. In certain variations, at least a portion of thefiber positioned within the lumen of the elongate instrument may bedecoupled or free floating relative to the lumen of the elongateinstrument.

In certain variations, the system may be removably coupled to aninstrument driver and a controller which controls actuation of theelongate instrument, wherein actuation motion is transferred from thecontroller to the system via the instrument driver to articulate thedistal portion of the elongate instrument in at least one degree offreedom. Any of the systems described herein may be disposable.

In certain variations, the housing may include a registration fixture.Optionally, a fixed portion of the fiber and the service loop may bepositioned on a single registration fixture. The registration fixturemay include grooves for holding at least a portion of the service loop.A service loop may be configured to slide in a single plane within theregistration fixture. In certain variations, a registration fixture mayinclude grooves for holding at least a portion of the fiber or at leasta portion of the elongate instrument in a known shape, orientation orposition.

In certain variations, a method of actuating an elongate instrument mayinclude one or more of the following steps. An assembly may beoperatively coupled to a controller. The assembly may include anelongate instrument; a housing coupled to a proximal portion of theelongate instrument, wherein the housing comprises an interface forreceiving an actuating force and transferring the actuating force to theelongate instrument to articulate a distal portion of the elongateinstrument; and a shape sensing fiber. At least a first portion of thefiber may be positioned in the lumen of the elongate instrument. Atleast a second portion of the fiber may be positioned in the housingsuch that the coordinate system of the fiber can be matched to thecoordinate system of the elongate instrument to register the fiber tothe elongate instrument. The second portion of the fiber may include aservice loop. Actuation motion may be transferred from the controller tothe assembly to articulate the distal end of the elongate instrument inat least one degree of freedom. The service loop may allow the fiber toslide or displace within the lumen of the elongate instrument when thedistal portion of the elongate instrument is articulated, therebycontrolling the amount of strain the fiber is subjected to. Savedregistration data regarding registration between the coordinate systemof the fiber and the coordinate system of the elongate instrument may beaccessed from a memory component to determine the shape of the elongateinstrument.

In certain variations, at least a portion of the second portion of thefiber may be fixed such that one or more degrees of freedom of the fixedportion the fiber may be measured or ascertained relative to theelongate instrument. In certain variations, at least a portion of thesecond portion of the fiber may be configured in a known shape, plane orother orientation such that one or more degrees of freedom of theportion of the fiber may be measured or ascertained relative to theelongate instrument. In certain variations, at least a portion of thefiber positioned within the lumen of the elongate instrument may bedecoupled or free floating relative to the lumen of the elongateinstrument.

In certain variations, a system may be removably coupled to aninstrument driver and a controller which controls actuation of theelongate instrument, wherein actuation motion is transferred from thecontroller to the system via the instrument driver to articulate thedistal portion of the elongate instrument in at least one degree offreedom. In certain variations, the housing may include a registrationfixture. Optionally, the service loop may have a shape configured to fitsubstantially within a registration fixture.

In any of the variations described herein, an elongate instrument mayinclude one or more lumens. For example, the elongate instrument mayinclude a primary lumen and one or more secondary lumens.

Each of the individual variations described and illustrated herein hasdiscrete components and features which may be readily separated from orcombined with the features of any of the other variations. Modificationsmay be made to adapt a particular situation, material, composition ofmatter, process, process act(s) or step(s) to the objective(s), spiritor scope of the present invention.

Methods recited herein may be carried out in any order of the recitedevents which is logically possible, as well as the recited order ofevents. Furthermore, where a range of values is provided, everyintervening value between the upper and lower limit of that range andany other stated or intervening value in that stated range isencompassed within the invention. Also, any optional feature of theinventive variations described may be set forth and claimedindependently, or in combination with any one or more of the featuresdescribed herein.

All existing subject matter mentioned herein (e.g., publications,patents, patent applications and hardware) is incorporated by referenceherein in its entirety except insofar as the subject matter may conflictwith that of the present invention (in which case what is present hereinshall prevail). The referenced items are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as an admission that the present invention isnot entitled to antedate such material by virtue of prior invention.

Reference to a singular item, includes the possibility that there areplural of the same items present. More specifically, as used herein andin the appended claims, the singular forms “a,” “an,” “said” and “the”include plural referents unless the context clearly dictates otherwise.It is further noted that the claims may be drafted to exclude anyoptional element. As such, this statement is intended to serve asantecedent basis for use of such exclusive terminology as “solely,”“only” and the like in connection with the recitation of claim elements,or use of a “negative” limitation. Unless defined otherwise, alltechnical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skill in the art to which thisinvention belongs.

This disclosure is not intended to be limited to the scope of theparticular forms set forth, but is intended to cover alternatives,modifications, and equivalents of the variations described herein.Further, the scope of the disclosure fully encompasses other variationsthat may become obvious to those skilled in the art in view of thisdisclosure. The scope of the present invention is limited only by theappended claims.

What is claimed is:
 1. A system comprising: (a) an elongate instrumentcomprising a proximal end and a distal end, the elongate instrumentdefining a neutral axis; (b) one or more control wires coupled to thedistal end of the elongate instrument, the one or more control wiresconfigured to control movement of the distal end of the elongateinstrument; (c) a registration fixture coupled to the proximal end ofthe elongate instrument, the registration fixture defining a serviceloop groove, the service loop groove being offset from the neutral axisof the elongate instrument; and (d) a shape-sensing fiber extendingalong at least a portion of the elongate instrument and affixed to theregistration fixture, wherein a distal portion of the shape-sensingfiber is disposed in the elongate instrument, wherein a proximal portionof the shape-sensing fiber is positioned in the service loop groove ofthe registration fixture such that the proximal portion of theshape-sensing fiber is out of plane relative to the elongate instrument,the service loop groove being configured to receive slack in the shapesensing fiber and thereby allow the shape-sensing fiber to travel as theelongate instrument bends.
 2. The system of claim 1, wherein the neutralaxis is configured to maintain a path length during bending of theelongate instrument.
 3. The system of claim 1, wherein the offsetportion of the shape-sensing fiber is positioned along an outside of theelongate instrument.
 4. The system of claim 1, wherein the offsetportion of the shape-sensing fiber is positioned in one or more lumensin a wall of the elongate instrument.
 5. The system of claim 1, whereinthe shape-sensing fiber is anchored to the elongate instrument offsetfrom the neutral axis of the elongate instrument.
 6. The system of claim1, wherein the shape-sensing fiber is configured to slide or floatwithin a lumen of the elongate instrument.
 7. The system of claim 1,wherein at least a portion of the shape-sensing fiber is free floatingwithin the service loop groove.
 8. The system of claim 1, wherein theservice loop groove comprises an open end, and wherein the shape-sensingfiber is configured to be top loaded within the open end.
 9. The systemof claim 1, wherein the service loop groove comprises a height largerthan a diameter of the shape-sensing fiber, wherein the service loopgroove comprises a width, and wherein the width of the service loopgroove varies along a length of the service loop groove.
 10. The systemof claim 1, wherein the service loop groove comprises a straightportion.
 11. The system of claim 1, wherein the service loop groove isconfigured to allow the shape-sensing fiber to travel a predetermineddistance.
 12. The system of claim 1, wherein the registration fixture isconfigured to facilitate calibration of the shape-sensing fiber to aknown structure of the registration fixture.
 13. The system of claim 1,wherein the shape-sensing fiber is affixed to the registration fixtureat a fixed point.
 14. The system of claim 13, wherein every location onthe shape-sensing fiber is measurable relative to the fixed point todetermine a relative position and a shape of the shape-sensing fiber.15. The system of claim 13, wherein the system is configured to match acoordinate system of the shape-sensing fiber to a coordinate system ofthe elongate instrument at the fixed point.
 16. The system of claim 1,wherein the elongate instrument is selected from a group comprising acatheter, an endoscope or a bronchoscope.
 17. A system comprising: (a)an elongate instrument comprising a proximal end and a distal end, theelongate instrument defining a neutral axis; (b) one or more controlwires coupled to the distal end of the elongate instrument, the one ormore control wires configured to control movement of the distal end ofthe elongate instrument; (c) a registration fixture comprising a plate,the registration fixture coupled to the proximal end of the elongateinstrument, the plate including a first curved surface having a firstradius of curvature and a second curved surface having a second radiusof curvature, the second curved surface facing the first curved surface,the first and second curved surfaces cooperating to define a serviceloop groove; and (d) a shape-sensing fiber extending along at least aportion of the elongate instrument and affixed to the registrationfixture, wherein a proximal portion of the shape-sensing fiber ispositioned within the service loop groove, and wherein the service loopgrove allows the shape-sensing fiber to travel from the first curvedsurface toward the second curved surface as the elongate instrumentbends.
 18. The system of claim 17, wherein the plate comprises a trackconfigured to guide the shape-sensing fiber from the proximal end of theelongate instrument into the service loop groove.
 19. The system ofclaim 17, wherein the first radius of curvature is at least 15 mm. 20.The system of claim 19, wherein the service loop groove is configured toprevent the shape-sensing fiber from bending below a minimum bendradius.
 21. The system of claim 19, wherein the service loop groovefurther comprises a spiral portion.